Lateral neck fistula - causes, symptoms, diagnosis and treatment. Median and lateral neck cyst: treatment. Why is a cyst dangerous?

26.3. LATERAL CYSTS AND FISTULAS OF THE NECK

Lateral neck cyst(synonyms: congenital lateral neck cyst; gill cyst; branchiogenic cyst; lateral branchiogenic neck cyst; lateral lymphoepithelial cyst), according to our data, are found in 25% of all soft tissue cysts of the maxillofacial area and neck. Lateral neck fistulas are rarely detected.

There are still disagreements regarding the pathogenesis of lateral cysts and fistulas. There are two theories of their origin. According to "thymic" theories, these cysts and fistulas are formed from the remains thymopharyngeal (pharyngeal) duct.Branchiogenetic the theory connects the origin of these formations with a developmental anomaly gill (pharyngeal) pouches. Anomalies in the development of the 2nd or 3rd pair of pharyngeal (gill) pouches are the source of the formation of lateral cysts and fistulas of the neck. From the 4th and 5th pharyngeal pouches, fistulas usually do not form due to the underdevelopment of the pockets and their early closure in the cervical sinus. The internal branchiogenic pockets are formed by the endoderm, and the external ones (or grooves) by the ectodermal germ layer. Lateral neck cysts can be of either endodermal or ectodermal origin. (Fig. 26.3.1).

Rice. 26.3.1 Scheme of location of branchiogenic fistulas of the neck: 1 - I gill pouch; 2 - II gill pouch; 3 - III gill pouch; 4 - auditory tube; 5 - tongue; 6 - thyroid-lingual duct; 7 - hyoid bone; 8 – thyrohyoid membrane; 9 – thyroid cartilage; 10 - common carotid artery; 11 - thyroid gland; 12 – parathyroid glands.

Cysts can occur at any age, but are more common in children and young people. Their appearance is preceded by infectious diseases respiratory tract(sore throat, flu, etc.). Unlike dermoid (epidermoid) cysts, lateral cysts often suppurate.

Clinic . Lateral cysts are rounded formations located in upper section neck in front of the sternocleidomastoid muscle (in the area of ​​the carotid triangle). Although it may be on average and even lower section neck. In typical cases, the lateral cyst, localized in the upper or middle third of the neck, is adjacent to the anterior edge of the sternocleidomastoid muscle or partially extends under it. It is located between the 2nd and 3rd fascial layers of the neck (between the superficial and deep layers of the fascia of the neck) on the neurovascular bundle. Upper pole The cyst is often located near or under the posterior edge of the digastric muscle or stylohyoid muscle. Medially cysts are adjacent to the inner jugular vein at the level of the bifurcation of the common carotid artery. The length of the cyst can extend down to the collarbone or in the upper part of the neck it can reach the mastoid process.

Visually, a lateral neck cyst appears as a painless, limited, rounded tumor-like formation with smooth surface (Fig. 26.3.2). The skin over it is not changed in color. Not fused with surrounding tissues. During swallowing movements, the tumor-like formation does not move (unlike midline cysts of the neck). The consistency of the cyst is soft-elastic or elastic-tense (dense-elastic). Fluctuation may be detected. The cyst does not cause breathing or swallowing problems. Common manifestations No. When secondary inflammation occurs, the cyst becomes dense, inactive, painful, and can cause pain when swallowing and even talking. General symptoms appear (malaise, weakness, increased body temperature, etc.). By puncturing the cyst, you can obtain a serous-mucous or mucopurulent transparent liquid of a light brown or dark brown (rarely) color. When the cyst suppurates, the fluid becomes cloudy and pus appears. Microscopically, desquamated epithelial cells, erythrocytes, lymphocytes, and cholesterol crystals can be detected in the punctate. When bacteriological examination of the contents of an uncomplicated cyst, microflora is usually not detected. Only in isolated cases are low-virulent staphylococci or streptococci isolated.

Rice. 26.3.2. Appearance of patients with lateral neck cysts: a, b - c adolescence; c, d - c at a young age; d - in old age.

Pathomorphology . Microscopically, the wall of the lateral cyst consists of dense fibrous connective tissue, which is lined with both stratified squamous non-keratinized epithelium (ectodermal cyst) and stratified columnar epithelium (endodermal cyst). In the thickness of the wall (shell) there is lymphoid tissue, often forming follicles. Significant development lymphoid tissue indicates that lateral cysts originate from remnants gill apparatus. The inner surface of the cyst may be covered with warty growths of lymphoid tissue. In its wall formations such as thymus gland bodies are detected.

When lateral cysts suppurate, the epithelium may partially die and be replaced by connective tissue; thickening of the epithelial lining and its keratinization are observed. At the lower pole of the lateral cyst, it is very often morphologically detected lymph node.

D diagnostics lateral cysts is carried out with chronic lymphadenitis (nonspecific and specific), dermoid (epidermoid) cysts, tumors and tumor-like formations of soft tissues of the neck, blood vessels, nerves and thyroid gland, metastases of malignant tumors, etc. To clarify the diagnosis, cysto- or fistulography can be performed with the introduction radiopaque agents (Fig. 26.3.3).

Rice. 26.3.3. Cystography of a lateral neck cyst.

Lateral neck cysts should be differentiated from diverticula of the esophagus. The round formation is located in front of the sternocleidomastoid muscle. Soft or doughy to the touch, collapses upon palpation and transmits a peristaltic wave when swallowing. When eating, it fills and increases in size. The pain intensifies when the diverticulum fills after eating. Swallowing can be painful, especially when the inflammatory process worsens.

Treatment lateral cysts are surgical only. Surgical intervention is a difficult task due to the complex anatomical and topographic relationships of the cyst with the vessels and nerves of the neck. The operation is performed under endotracheal anesthesia. The incision should be made along the anterior edge of the sternocleidomastoid muscle. Non-radical surgical intervention leads to relapse.

Complications lateral cysts may be phlegmon of the neck and branchiogenic cancer. Cellulitis of the neck is severe with severe intoxication of the patient’s body. The purulent-inflammatory process can easily spread along the neurovascular bundle into the anterior mediastinum. The development of branchiogenic cancer, according to our clinic, occurs in about 4.5% of patients with lateral neck cysts. The high percentage of development of branchiogenic cancer in these patients necessitates early removal of lateral neck cysts.

Lateral neck fistulas can be formed as a result of suppuration and opening of the lateral cyst, but are often congenital in nature (formed in the prenatal period). Fistulas from the 1st pharyngeal pouch open on the skin in the area of ​​the earlobe or in the periauricular area; they can communicate with the middle ear and the auditory (Eustachian) tube. Fistulas emanating from the 2nd branchial pouch open in the fossa above the palatine tonsil, and on the skin - in front of the sternocleidomastoid muscle in the middle or lower part of the neck (the fistula passes between the branches of the common carotid artery, going down, following in front and outward from it ). When fistulas develop from the 3rd branchial pouch, they open in the lower part of the lateral surface of the pharynx (below the palatine tonsil), move down, bending around the common carotid artery from behind and on the side, and emerge in front of the sternocleidomastoid muscle below the neck line.

There are lateral neck fistulas full And incomplete(external And internal). The internal opening of a complete lateral and incomplete internal fistula opens in the area of ​​the palatine tonsil. Incomplete internal fistula of the neck begins in soft tissues at the level of the thyroid cartilage. The course of the fistula is complex and passes in close proximity to the large vessels of the neck. External holefull And external incomplete lateral fistula located on the skin at the inner edge of the sternocleidomastoid muscle in the middle (usually) or lower third of the neck. External incomplete fistula of the neck ends in the soft tissues at the level of the thyroid cartilage.

Clinically skin (external) opening (orifice) lateral fistula is often punctate, less often - wide with lush granulations. Around the mouth of the fistula, due to frequent discharge, the skin becomes wet and macerates. When pressure is applied, a drop of transparent mucous contents, and sometimes pus, is released from the mouth of the fistula. Probing such a fistula with an ocular probe or a thin polyethylene catheter can penetrate to a depth of 1-2 cm to 8-15 cm. To clarify the course of the fistula, fistulography is done with the introduction of oil radiopaque substances. To identify the location of the internal opening of the lateral neck fistula, a solution of brilliant green or methylene blue is injected into its external opening. By staining the fabrics where the dye exits, one can judge the location of the internal hole.

Branchiogenic (lateral) fistula of the neck should differentiate from the thyroglossal (median) fistula, the external opening of which can also be shifted away from midline. Diagnosis must be carried out with specific inflammatory processes of soft tissues, branchiogenic cancer, metastases of malignant tumors, etc.

Pathomorphology . Microscopically, the wall of the fistula corresponds to the structure of the wall of the lateral cyst of the neck.

Treatment lateral (branchiogenic) fistulas of the neck surgical. To clarify the course of the fistula, during the operation, it should be filled with dyes (solutions of brilliant green or methylene blue). Incomplete excision of the fistula or its branches leads to relapse of the disease.

Congenital cysts and fistulas of the neck are divided into median and lateral. Their occurrence is associated with a violation of the formation of this area in the embryonic period. The most common are median cysts and fistulas. Localization of cysts and fistulas is shown in the figure:

Median cysts and fistulas of the neck. According to most surgeons, such cysts and fistulas are the result of a violation of the reverse development of the thyroid-lingular duct. Median primordium thyroid gland, located in the sublingual region, then descends to the neck, passing through the hyoid bone. Along the path of the descent of the rudiment, an embryonic tract remains, which is normally obliterated. At complete absence obliteration, median fistulas occur; when a closed cavity is formed, median cysts of the neck occur.

Clinic and diagnostics. A median neck cyst is rarely diagnosed in children under 1 year of age. The cyst is located in the midline of the neck, has a soft-elastic consistency, and fluctuates. Its palpation is painless. When swallowing, the upward displacement of the tumor-like formation along with the hyoid bone is clearly visible. It is often possible to palpate a dense cord extending from the upper pole of the cyst. Usually the diameter of the cyst does not exceed 2-3 cm, but gradually, with age, its contents increase and the size of the cyst increases. When suppuration occurs local symptoms- hyperemia, swelling, fever, pain when swallowing. The cause of suppuration can be either a hematogenous infection or spread through thin fistulous tracts running from the cyst to the oral cavity.

Median neck cysts are usually formed as a result of spontaneous opening of a suppurating cyst, and sometimes after surgery, also located along the midline of the neck. The fistula is sometimes pinpoint and difficult to discern, but can be seen quite well. Upon palpation, a dense cord is determined, usually running towards the hyoid bone. Sometimes, the fistula goes to the manubrium of the sternum. Fistulas are detected by the presence of mucous discharge, which in complicated cases becomes mucopurulent or purulent. Microscopic examination of the discharge reveals deflated squamous epithelial cells.

Probing, as a rule, fails due to the tortuous course of the fistula. A median neck fistula is recognized very easily, while the diagnosis of a neck cyst is often difficult.

It is often necessary to differentiate midline cysts of the neck from dermoid cysts, lipomas, lymphangiomas, and in complicated cases from lymphadenitis. A dermoid cyst, unlike a neck cyst, is denser, does not move when swallowing, and the cord (a remnant of the embryonic tract) is not palpable. Lymphangioma and lipoma are usually large in size, without clear boundaries, have a soft, elastic consistency, and their contents often increase. When recognizing lymphadenitis great importance have anamnesis data and identification of the entrance gates of infection.

Treatment. Median cysts and fistulas are removed surgically. The operation is indicated for people over 3 years of age. Before the operation, a dye is injected into the fistula tract. When isolating the embryonic duct, the hyoid bone must be resected, and the fistula is ligated at the base.

Relapses occur in cases where the embryonic duct is not completely removed. The prognosis if the operation is performed correctly is favorable.

Lateral cysts and fistulas of the neck. The occurrence of lateral cysts and fistulas of the neck is associated with a violation of the obliteration of the ducts of the thymus gland, which, starting on the side wall of the pharynx, pass through the entire neck and end at the sternum. Some authors believe that lateral cysts and fistulas of the neck originate from the remains of the branchial cleft (brachiogenic cysts and fistulas).

Clinic and diagnostics. Lateral cysts and fistulas are located on the inner surface of the sternocleidomastoid muscle. Lateral cysts are formations of round or oval shape, tight-elastic consistency, with clear boundaries. The skin over them is not changed, palpation is painless. Lateral fistulas are pinpoint openings with mucous discharge.

a - middle; b - side

Complete fistulas communicate with the pharyngeal cavity, opening behind the posterior palatine arch. A dense cord is palpated along the fistulous tract in the neck. When infected, the discharge from the fistula becomes purulent, and the surrounding skin macerates.

Lateral cysts most often have to be differentiated from lymphangioma. For diagnosis, the location and consistency of the tumor and the presence of a fistulous tract under the skin are important.

When lateral cysts become infected, they are differentiated from lymphadenitis. Anamnesis data helps to make the correct diagnosis.

Treatment. Lateral cysts and fistulas are removed surgically; Treatment is carried out over the age of 3 years. For a better cosmetic effect, a double incision is performed. The fistula is isolated up to the side wall of the pharynx. In case of complete fistulas, their proximal part is turned inside the pharyngeal cavity using a probe, and the hole is sutured. Errors in technique - incomplete removal of fistulas, leaving lateral holes - lead to relapse, the frequency of which reaches 10%.

Among them there are branchial (from the Greek branhia - gills) and thyroglossal cysts and fistulas. The occurrence of a branchial cyst and fistula is associated with an anomaly in the development of the 1st and 2nd branchial slits and arches. Thyroglossal cyst and fistula are formed due to incomplete reduction of the thyroglossal duct in the embryo. Congenital cysts and fistulas are relatively rare and account for about 5% of all neoplasms of the face and jaws. Anomaly of the gill slits is observed more often than the thyroglossal one (61 and 39% of cases, respectively).

Congenital cysts are observed mainly in children and persons young. Clinical course branchial and thyroglossal cysts and fistulas are similar, but they have their own characteristics, due to localization.

The cyst grows slowly over several years. It is defined as a painless limited formation of round or oval shape, elastic consistency, not fused to the skin. The cyst is discovered accidentally or when inflammation occurs. In the case of the addition of specific microflora (mycobacterium tuberculosis, actinomycetes), diagnosis becomes difficult.

Congenital fistulas can be complete, with two outlets: external - on the skin, internal - on the mucous membrane of the oral cavity, and incomplete - with one mouth, external or internal. In the diagnosis of fistulas, contrast fistulography using iodolipol is important. It allows you to determine the direction, extent and presence of branches of the fistula, knowledge of which is necessary for surgical treatment.

Branchial cysts and fistulas. With pathology of the 1st branchial cleft, a cyst or fistula occurs in the parotid region, external ear canal And auricle. An anomaly in the development of the 2nd branchial cleft leads to the formation of a lateral cyst or fistula of the neck. Branchial cysts and fistulas of the parotid region are much less common (11%) than lateral cysts and fistulas of the neck (89%).

Cyst and fistula of the parotid region. The cyst is located under the main mass of the parotid salivary gland or in the retromaxillary region above the trunk facial nerve and often has a connection with the cartilaginous portion of the external auditory canal. Clinical manifestations the same as with benign tumor or parotid cyst.

A branchial fistula with an outlet on the skin located in front of the base of the helix of the auricle is called preauricular. It is often bilateral. Celebrated role hereditary factor in his education.

A fistula of the retromaxillary region is formed as a result of independent or surgical opening of a suppurating branchial cyst; its external opening is located between the angle lower jaw and the anterior edge of the sternocleidomastoid muscle. With complete preauricular and retromandibular fistulas, the second hole opens on the skin of the cartilaginous part of the external auditory canal; with an incomplete fistula, the walls of the latter are woven into it. A thin discharge from the fistula is noted, and the surrounding skin is often macerated. Microscopically, the internal lining of the fistula and cyst of the parotid region is represented by stratified squamous keratinizing epithelium.

Lateral cyst and fistula of the neck. A cyst is observed more often than a fistula (9:1). It has a typical localization, located in the upper third of the neck, in front of the sternocleidomastoid muscle, on the neurovascular bundle, directly adjacent to the internal jugular vein, and is a limited round-oval formation. On palpation - elastic consistency with signs of fluctuation, painless, somewhat mobile, not fused to the skin. It is especially well contoured when the patient's head is turned in the opposite direction. The contents of the cyst are a turbid, off-white liquid, a cytological examination of which reveals an oxyphilic fine-grained mass with elements of stratified squamous epithelium and a significant number of lymphocytes. When infected, the cyst becomes painful and quickly enlarges. Often the inflammatory process spreads to surrounding tissues. In such cases, the cyst is difficult to differentiate from lymphadenitis and adenophlegmon. A non-suppurating lateral cyst is differentiated from extraorgan tumors of the neck (neurinomas, lipomas), lymphogranulomatosis, etc. Microscopically, the wall of the cyst is lined with stratified squamous epithelium.

Diagnosis of a lateral cyst is based on anamnestic and clinical data. Receiving by puncture large quantity characteristic contents (5-30 ml) and cytological examination data allow us to confirm the diagnosis of a lateral cyst.

Lateral neck fistula can be unilateral and rarely bilateral. It is discovered in some cases at the birth of a child, in other cases it is the result of opening a suppurating lateral cyst of the neck. The external mouth of the fistula is located on the skin of the lateral surface of the neck, corresponding to the anterior edge of the sternocleidomastoid muscle. The internal mouth of a complete lateral fistula is permanently localized in the upper pole of the palatine tonsil. In depth, the fistula passes between the external and internal carotid arteries.

Clinically, the external mouth of the fistula can be pinpoint or widened with bulging granulations, sometimes covered with weeping crusts. Hyperpigmentation and maceration of the skin around the fistula are determined due to the constant release of a yellowish viscous liquid from it. In the presence of a complete lateral fistula, patients often indicate a history of recurrent unilateral tonsillitis; upon examination, an enlargement of the tonsil of the corresponding side is determined.

A lateral neck fistula must be differentiated from a median fistula, the external mouth of which is sometimes displaced away from the midline, and a specific inflammatory process.

The microscopic picture of the lining of the fistula corresponds to the structure of the wall of the lateral cyst of the neck.

Thyroglossal cyst and fistula have a typical localization along the midline of the neck, and therefore they are also called midline.

The thyroglossal cyst is located in the midline of the neck in the sub- or suprahyoid region and at the root of the tongue. When localized on the neck, a dense formation is determined, with a diameter of no more than 2 cm, round in shape, with clear boundaries, elastic consistency, not fused to the skin. On palpation, painlessness, limited mobility, adhesion to the body of the hyoid bone are noted, which is clearly detected when swallowing. With a cyst of the root of the tongue, the latter is raised, speech impairment and difficulty swallowing are noted.

Infection of the contents of the cyst leads to pain, swelling, and infiltration of surrounding tissues. In these cases clinical picture resembles that of lymphadenitis or abscess. With frequent recurrences of a tongue abscess, the presence of a cyst at its root should be suspected.

The contents of the thyroglossal cyst are a turbid yellowish viscous liquid. Cytological examination The presence of stratified squamous epithelial cells and lymphoid elements was established. The epithelium of the cyst shell, like the lining of the median fistula, is of endodermal origin.

Thyroglossal fistula occurs, as a rule, after spontaneous or surgical opening of the median cyst of the neck. The external mouth of the fistula is located on the skin along the midline of the neck, mainly between the hyoid bone and the thyroid cartilage. The skin is often scarred, sometimes granulations grow around the fistula. The discharge is scanty and mucus-like. With a complete fistula, the internal opening is located in the area of ​​the foramen coecum

The thyroglossal fistula passes along the midline of the neck, pierces the body of the hyoid bone and at an angle of 40-45o is directed towards the blind foramen of the tongue. By palpation, the fistulous tract, as well as the median cyst of the neck, is always associated with the body of the hyoid bone. This is defined as follows. Holding the fistula or cyst with a finger, the patient is asked to swallow saliva, while displacement of the fixed formations along with the hyoid bone indicates the presence of a thyroglossal fistula or cyst.

Differential diagnosis of a median cyst and fistula is carried out with specific inflammatory process, lymphadenitis, dermoid cyst, with struma of the tongue or adenoma of the dystopic thyroid gland.

Treatment is complete excision of the cyst with capsule. If inflammation is present, the operation is performed after its elimination. The cyst of the retromaxillary region is removed through an incision bordering the angle of the lower jaw, and 1.5-2 cm away from it, so as not to damage the marginal branch of the facial nerve. To remove a lateral neck cyst, a skin incision is made above the cyst along the anterior edge of the sternocleidomastoid muscle or along the upper cervical fold. For a thyroglossal cyst, the skin is incised along the upper or middle fold of the neck; removal of the cyst is combined with resection of the body of the hyoid bone. A tongue root cyst, depending on its size, is operated on either with an intraoral or external approach.

Excision of the fistula is preceded by filling it before surgery 1% aqueous solution methylene blue. In this case, the wall of the fistula is painted and is clearly visible during removal. The operation consists of excision of the fistula with its branches. An incision is made bordering the external mouth of the fistula, it is prepared and the fistula is isolated. Removal of preauricular and retromandibular fistulas is completed by excision of the cartilaginous portion of the external auditory canal. Operation for a complete lateral fistula of the neck is associated with certain difficulties associated with the topographic relationship of the fistula and the neurovascular bundle of the neck: the fistula tract passes in its bed between the external and internal carotid arteries. Excision of the thyroglossal fistula, like cysts, is accompanied by resection of the body of the sublingual salivary gland.

"Surgical Dentistry" edited by Robustova T.G.

Fourth edition. Moscow "Medicine" 2010

Clinical cases:

MEDIUM CYST OF THE NECK

Page 51 of 103

Congenital fistulas and cysts of the neck are either median or lateral, with the median being much more common than the lateral.
Congenital fistulas and cysts of the neck are formed from the remnants of the epithelial ducts that existed in the embryo, which, when normal conditions its developments are obliterated. If this reverse development from the remains is disrupted epithelial course Cysts and fistulas form. Embryologically, median cysts and fistulas originate from the remains of the ductus thyreo-glossus, lateral fistulas - from the ductus thymo-pharyngeus.
Following short description embryological data concerning the ductus thyreo-glossus and ductus thymo-pharyngeus explains the formation of cysts and fistulas of the neck.
In a two-week-old embryo, a depression lined with ciliated epithelium appears on the anterior surface of the primary mouth. Gradually developing deeper, this passage turns into a canal lined with cells characteristic of the embryonic thyroid gland. This glandular formation soon divides into two lobes. While its lower end continues to grow, it top part, that is, the canal undergoes regressive changes, and its opening at the root of the tongue remains forever in the bidet foramen coecum. Around the fifth week of uterine life, the canal disappears. If this canal remains open for a greater or lesser extent, a median fistula or neck cyst occurs. Microscopic studies R.I. Venglovsky on the corpses of both adults and children pointed to interesting fact that in every third person, i.e. in more than 30% of cases, can be found all the way from foramen coecum to thyroid cartilage then small lobules of the thyroid gland, then small tubules, then, finally, small cysts - in a word, certain remnants of the development of the middle thyroid lobe.
Regarding the origin of lateral fistulas, there are indications in the literature that they arise from the remains of gill slits, which is why they are also called branchiogenic fistulas.
Through research on human embryos and corpses, R.I. Venglovsky was able to prove that just as median fistulas arise from the remnants of the thyroid-lingual canal, lateral fistulas arise from the remnants of the unovergrown goitrous-pharyngeal duct (ductus thymo-pharyngeus). The embryo has two goitrous-pharyngeal ducts, located symmetrically on the sides of the neck. Starting on the side wall of the pharynx, each of these ducts runs obliquely across the entire neck and ends at the sternum. Here the canal begins to thicken and turns into glandular, lymphoid tissue, typical of the thymus gland. By the end of the second embryonic month of life, the ductus thymo-pharyngeus, like the ductus thyreo-glossus, disappears. However, Venglovsky showed that in 14% of cases remains of the thymus-pharyngeal canal can be found from the pharynx to the sternum. Thus, according to Venglovsky, lateral fistulas arise not from the gill slits, but from the remains of the ductus thymopharyngei.
Indeed, lateral fistulas follow the course of the thymus canal: starting on the lateral wall of the pharynx near the tonsil, they go down next to hypoglossal nerve and go down along vascular bundle. Here, being closely connected with the sheath of the vessels, these fistulas stretch along the medial edge of the sternocleidomastoid muscle to the sternum.
While agreeing with Venglovsky on the issue of the genesis of lateral fistulas and cysts, we cannot, however, completely exclude the possibility of the development in some cases of these formations from the gill slits.
Depending on the size of the remaining part of the embryonic canal, the length of the fistulas varies. Both median and lateral fistulas rarely have a length corresponding to the entire embryonic duct. Only in selected in rare cases median fistulas maintain patency from the thyroid cartilage to the foramen coecum linguae, and lateral ones - from the neck to the lateral wall of the pharynx. It is determined microscopically that the canal of the median and lateral fistula tract or the cyst cavity is lined with columnar or ciliated epithelium; at the ends of the fistula, both below and above, this epithelium becomes squamous. Sometimes lymphoid tissue of the thyroid and thymus glands is found in the wall of the fistula.
Clinic. Median fistulas very rarely exist from birth. Usually, a few months after birth, and sometimes years, a round-shaped tumor appears on the midline of the neck, which slowly grows. The tumor is located above the thyroid cartilage near the hyoid bone. The size of the tumor varies - from a pea to a large plum. It is painless, soft-elastic consistency, and fluctuates. The tumor is tightly fused to the underlying tissues and moves upward during swallowing movements. The skin over it is unchanged and mobile.
Median cysts can exist for years without causing complaints and slowly enlarging. In most cases, they become infected, after which they begin to quickly increase in size and open either independently or as a result surgical intervention a doctor who mistakes such an inflamed cyst for a suppurating lymph node. A fistula is formed from the opened cyst, which has no tendency to heal; mucopurulent discharge in greater or lesser quantities passes through it for years. In some cases, the fistula temporarily closes, but after some time the remaining course, in which the contents accumulate, becomes inflamed, and the fistula opens again in the same place or next to the old scar. Thus, median fistulas usually form after the cyst has been opened. The opening of the fistula is located near the midline below the hyoid bone. When palpating above the opening of the fistula, it is possible to palpate a dense cord running along the course of the fistula to the hyoid bone. If this strand can be grasped well with your fingers, then when swallowing you can clearly feel its connection with the breathing tube. When pressing on the fistulous tract, mucous, often mucopurulent, contents are released from its opening. Probing the fistula tract is difficult, since it is narrow, tortuous and the probe only reaches the hyoid bone. To prove the connection of the fistula with the oral cavity, you can inject a colored liquid into it, which is released through the blind opening of the tongue, if the canal is preserved along its entire length.
Diagnostics median cysts and fistulas are not difficult. Most common mistake associated with purulent lymphadenitis. An inflamed cyst is mistaken for a festering node, and a fistula that does not heal gives reason to think about the tuberculous nature of the lesion. A careful examination, localization of the fistula, palpation of the cord along the fistula and the absence of damage to other nodes make it easy to make the correct diagnosis.
The only right thing treatment median cysts and fistulas - their excision. The operation rarely has to be performed on children under one year of age.
However, you should not postpone the operation of removing the median cyst, but it is better to perform it in the first years of life. As observations from our clinic have shown, the largest number of relapses was obtained after the operation of excision of fistulas. Therefore, it is advisable to operate before the cyst becomes inflamed and a fistula forms. During surgery, it is necessary to completely remove the cyst wall and the fistula along its entire length. This sometimes presents significant difficulties since the course of the fistula is thin and easily breaks off when it is isolated near the hyoid bone. In addition to the main passage, median fistulas often have additional lateral passages in the form of pockets. Leaving these pockets leads to recurrence of the fistula. We have seen patients who were operated on several times before the fistula was completely excised. Inserting a probe or colored liquid into the fistula tract during surgery does not help much. The success of the intervention depends on careful anatomical tissue preparation.
The skin is dissected with a longitudinal or collar-shaped incision, and the fistula opening, together with the scarred skin, is excised with an outlining oval incision. To the hyoid bone selection is in progress relatively easy. The most crucial point is the separation of adhesions between the fistulous tract and the hyoid bone, under which it goes. After isolation, the cord is tied with catgut and cut off. Sometimes the passage goes through the bone, piercing it. In these cases, discharge is possible along with the bone. A piece of the hyoid bone (3-5 mm in size) around the cord is resected in small pieces. The fistula tract is then easily isolated, tied as high as possible with a catgut ligature and cut off. The hyoid bone does not need to be sutured. Sutures are placed on the neck fascia and skin.
During the first days after surgery, patients complain of pain when swallowing, so they should be fed liquid pureed food.
Lateral cysts are much less common than lateral fistulas. The latter, unlike the middle ones, mostly occur from the moment of birth. The fistula looks like a pinhole from a needle prick, from which a small amount is released. clear liquid. With age, the fistula tract becomes infected, sometimes causing an outbreak acute inflammation, and the discharge takes purulent character. The external opening of the lateral fistula is located along the anterior edge of the sternocleidomastial muscle. In older children, a dense cord can sometimes be felt along the upward course of the fistula. The surrounding skin may become irritated and inflamed. Fistulas can be complete or incomplete. Find out the question about full cross-country ability fistula, especially in small child, difficult. Sometimes the question of the length of the fistula and whether it reaches the pharynx can be resolved with the help of a colored liquid that is injected through the fistula. Lateral neck cysts are most often located between the larynx and the edge of the sternocleidomastial muscle, extending upward towards the vagina of large vessels to the pharynx. Diagnosis of lateral fistulas is not difficult. It is more difficult to recognize cysts, which sometimes cannot be distinguished from lymphangioma.
Treatment of lateral cysts and fistulas is only surgical. We recommend operating on lateral cysts no earlier than 5 months after birth. Lateral fistulas, which mostly produce insignificant discharge and cause little concern to the child, should be operated on later (after 5 years). In some cases, when the fistula produces copious discharge and becomes infected, the operation can be performed earlier. Technically, surgery for lateral fistulas presents significant difficulties due to their subtlety in young children.

26.2. MIDDLE CYSTS AND FISTULAS OF THE NECK

Median cysts and fistulas of the neck are embryonic dysplasia associated with non-closure of the thyroglossal duct. Therefore, their synonym is thyroglossal cysts and fistulas.

Rice. 26.2.1 Appearance of patients with median neck fistulas. a - in a middle-aged woman; b - in a child (there are scars on the skin after opening the ulcers).

This pathogenesis of their development is confirmed by the fact that median cysts and fistulas have a connection with the hyoid bone and the blind foramen located in the area of ​​the root of the tongue. This type of congenital cysts and fistulas, according to our observations, accounts for about 7% of all soft tissue cysts of the maxillofacial area and neck. They occur more often in children and young people, but can also be detected in older people (Fig. 26.2.1).

WITH
radicular (thyroglossal) cysts grow slowly in the form of a painless rounded protrusion, which is usually located in the midline in the space between the hyoid bone and the upper edge of the thyroid cartilage. Sometimes you can find thyroglossal cysts, localized in the submandibular region, but connected by processes with the hyoid bone. In rare cases, the cyst is located behind the hyoid bone in the area of ​​the root of the tongue. Referred to as tongue root cysts, they have the same pathogenesis as median cysts, i.e. associated with an anomaly in the development of the thyroglossal duct.

Rice. 26.2.2. Fistulography of the median cyst and fistula of the neck.

The boundaries of the median cyst are clear and have a densely elastic or doughy consistency. The skin over the cyst is usually unchanged in color and mobile. The mobility of the cyst itself is limited due to its connection with the hyoid bone. Therefore, if you hold the median cyst with your fingers, then during swallowing movements it moves upward. In some cases, it is possible to palpate a dense cord going to the hyoid bone. When puncturing the cyst, you can get a yellowish liquid, sometimes cloudy. In the punctate, the presence of stratified squamous epithelial cells and lymphoid elements can be detected. When suppuration occurs, cysts produce pus.

Localized in the area of ​​the root of the tongue, the cyst causes difficulty swallowing and speech impairment, A if large, it can cause breathing problems. By palpation they are detected in the form of a round, fluctuating formation with clear boundaries, the surrounding tissues are not changed. After spontaneous or surgical opening of the abscess, fistulas occur. After the inflammatory phenomena subside, the fistulas usually close, but then recur.

Median (thyroglossal) fistulas divided into: full And incomplete.

Incomplete fistulas are divided into external And internal.

Full The median fistula begins (opens) on the anterior surface of the neck along the midline (may be displaced from the midline) between the hyoid bone and the thyroid cartilage, and in some cases may be located at the level of the hyoid bone or jugular notch. The internal opening of a complete median fistula opens in the area of ​​the blind foramen of the tongue. Thus, a complete fistula begins on the skin of the neck, then goes to the hyoid bone, penetrates through this bone and between the muscles of the floor of the mouth is directed obliquely upward and ends at the blind opening in the region of the root of the tongue.

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external incomplete median fistula begins (opens) on the skin of the neck and reaches the hyoid bone, ending blindly there. Internal incomplete median fistula neck goes from the hyoid bone to the blind foramen in the region of the root of the tongue.

Rice. 26.2.3. Ultrasound examination of a patient with a median cyst of the neck.

The skin around the external fistula is scarred, retracted, and may be macerated. In the underlying tissues, palpation reveals a dense cord that runs from the external fistula opening to the hyoid bone. The cord moves during swallowing movements. The fistula opening periodically closes, so scars can be seen in the area. After its spontaneous or surgical opening, pus is released from the fistula, and after the inflammatory phenomena subside, a scanty mucous or mucopurulent discharge is released.

Internal incomplete median fistulas may not manifest themselves in any way, because the outflow of contents is carried out into the oral cavity. Only if the outflow is disrupted, in the area of ​​the root of the tongue, can pain and the presence of inflammation be detected.

Pathomorphology median cysts and fistulas. The inner layer is lined with different epithelium (stratified squamous, transitional, cylindrical, undifferentiated, germinal). Under the influence of inflammation, the epithelium may partially die and be replaced by connective tissue. The lumens of the ducts narrow, become obliterated, and lateral branches appear. In the wall of cysts and fistulas one can find accumulations of lymphoid tissue, mucous glands and even thyroid tissue.

Diagnostics . To clarify the location and size of thyroglossal cysts and fistulas, cysto- or fistulography is used (Fig. 26.2.2). Contrast X-ray examination is carried out using oil or water-soluble X-ray contrast agents (Verografin, Urografin, etc.). At cystography First, the cyst cavity is punctured with a thick needle and the contents are sucked out, and then through an elastic catheter it is filled with a radiopaque substance and radiographs are taken in two projections (anterior and lateral). Fistulography performed using a blunt needle. It must be remembered that adhesive tape stickers cannot be used to cover the puncture site (insertion) of a needle because of their radiopacity, and therefore distortion of the true picture of the pathological focus. The puncture site is covered with a gauze swab and glued with cleol.

In recent years, ultrasound has been increasingly used to clarify the diagnosis. (Fig. 26.2.3) and computed tomography of the neck (Fig. 26.2.4).

Differential diagnosis congenital median (thyroglossal) cysts and fistulas must be carried out with the following diseases: specific inflammatory processes of soft tissues, chronic lymphadenitis, dermoids (epidermoids), ranulae, tumors of soft tissues and the thyroid gland.

We had to differentiate the median cyst from the air cyst of the neck. The latter occurs with increased intralaryngeal pressure and weakness of the muscular apparatus of the larynx. When you try to exhale air with your mouth closed and your nostrils compressed, the intralaryngeal pressure increases and the air cyst increases in size, which is not typical for a median cyst. When an air cyst is punctured, air is obtained and the cyst disappears for a while.

Rice. 26.2.4 Computed tomogram of the neck of a patient with a median cyst (a, b - different levels slices).

Treatment median cysts and fistulas surgical. Surgical treatment is not indicated only during the period of exacerbation of the inflammatory process. During this period, the formation is punctured, the purulent mucous contents are removed and the cavity is washed with antiseptic solutions. The operation is carried out after the elimination of inflammatory phenomena.

Conduct surgical treatment in children best at the age of 9-10 years. In earlier childhood, even in the absence of inflammatory phenomena, surgical intervention may be postponed due to technical difficulties that may arise during resection of the hyoid bone. Resection of the hyoid bone is the main condition for the radicality of the operation. To facilitate surgical intervention, a 1-2% alcohol solution of brilliant green is injected into the cavity of the cyst or fistula before surgery, which clearly stains the cyst shell and helps to establish the presence of all branches of the fistula. Resection of the hyoid bone is carried out over a length of 0.5-1 cm (depending on the width of the fistula). The fistulous tract can pass in close proximity to the epiglottis and aryepiglottic ligaments, injury to which can cause acute swelling of the larynx. Cause of relapses- non-radicality of the operation performed. Therefore, resection of the hyoid bone is a prerequisite when removing thyroglossal cysts and fistulas.