JOURNAL OF TRANSLATIONAL GASTROENTEROLOGY AND CLINICAL HEPATOLOGY (ISSN:2517-7419)

Branchial cleft (cervical lymphoepithelial) cyst, is a congenital (present at birth) lesion due to fragmentary extinction of the branchial apparatus, and obviously different from branchial cleft sinus, fistula or cartilage. In an archtypical non-infected case, it is a smooth, non tender, round mass, a derivative of the second branchial apparatus, existing in the anterolateral neck along the anterior border of the sternocleidomastoid muscle, deep alongside the internal jugular vein. Depending upon the arch of derivation the locus varies from anywhere in the external auditory canal to the clavicle and a connection with the pharynx in 95% of the cases. Third and fourth branchial cleft cysts (2-5%, the pyriform sinus fistulae) erroneously diagnosed as a bronchogenic cyst, are usually left sided, with neck infection and the treatment is ipsilateral thyroidectomy. The cysts enlarge evenly and are detected by the second/ third decade of life. Males are equally afflicted as females. Those appearing in childhood (20%) assume an acute and painful cystic enlargement; subsidiary to an upper respiratory infection .An infected cyst can advance to an abcess or burst to form a draining sinus tract. The size differs markedly with sufficient transillumination. When aspirated the contents are milky or purulent, if tenderly inflammed. A sinus tract or a blind pouch may be found. If the tract opens onto the surface of the skin, it is called a fistula, A true fistula, a communication between two epitheliazed surfaces, or the surface of the skin, may exist. The branchial fistulas are also pseudofistules, existing between remnants of a pouch with a skin opening consequent to an infection, or a surgical incision. A branchial pouch conjoins with the pharynx. Cysts are ten times more common than fistulae..The upper end of the sinus tract hardly ever extends to the tonsillar area. Branchial theory suggests a dormant and an abridged branchial cleft mucosa, unless activated to grow. More theories advocate persistence of the vestiges of the pre cervical sinus, the thymopharyngeal duct origin and a cystic lymph node origin GROSS exam demonstrates a smooth walled cyst with watery content, up to 10 cm in diameter. Inflammed/ruptured cysts are concealed by fibro inflammatory reaction enclosed within dense fibrosis.

The first branchial apparatus concedes a cyst or an infected fistulous tract preauricularly with the fistulous orifice anterior to the tragus, or the existence of cysts or sinus tracts in loci approximating the ear superior to mandibular altitude. These derangements are branched into Type I and Type II. Type I display only epidermal elements (like epidermal cysts), Type II lesions show ectoderm with skin appendages and intermittent mesodermal representation of cartilage. First branchial cleft cyst exhibit within the parotid. Rarely, persistence of the third branchial cleft, a cyst or a sinus is in affiliation with the hypopharyngeal pyriform recess. Analogy of the branchial cyst to lymphoid tissue was synonymised–tonsillar cyst.

Clinical Countenance: Notwithstanding the unspecified age, the second branchial cyst or fistula is customary in young adults. Neonatal patients/ larger cysts can manifest with an aerodigestive tract compromise with dyspnoea, stridor, dyspahgia, to aim for a neonatal life threatening airway obstruction. The cyst enlarges imperceptibly and infection accompanies an accelerated and accrued dimension. Suppuration of the bronchial fistulous aperture is discerned in the inferior neck. Branchial cleft sinuses and fistulae regularly exist directly at birth due to conspicuous apertures. In addition, fibrous cords are palpable, extending along the anterior border of the sternocleidomastoid. Mucus escapes from the exterior of the sinuses/fistulae, consequentially infected by cutaneous organisms viz staphylococcus aureus, group A beta haemolytic streptococci and be inherent to a purulent edema, erythema and seepage. An infected first branchial cleft sinus /fistula incites aural drainage in the deficiency of otitis media/ otitis externa. Paratracheal swelling collaborating with tenderness and fever may represent acute suppurative thyroiditis. Researchers have evidenced bacterial dissemination from an internal crevice in the pyriform fossa, in the third branchial cyst anomaly. 2 to 3% of the branchial cleft cysts are reciprocal and bilateral.

Diagnosis: Imaging, Fluoroscopic fistulography to anticipate the cyst, fistula, anatomic tract. Pyriform sinus exploration via direct larygnoscopy to ascertain third/fourth branchial cleft cyst abnormality.

Differential Diagnosis: First branchial cleft cyst, epidermoid cyst, dermoid cyst, cystic sebaceous lympadenoma. Second branchial cyst, lateral thyroglossal duct cyst, Third branchial cleft cyst papillary carcinoma thyroid with a cystic change (positive for TTF1 and, thyroglobulin). Fourth branchial cleft cyst with a thymic cyst.

Treatment: The sole competent treatment is surgical eradication of the cyst/ or a non- infected fistulous tract. Endoscopic cauterization via the pyriform sinus is recommended for oblishing the fourth branchial cyst. Circumstantial to the second branchial cleft cyst, the fistulous tract advances upwards between the external and the internal carotid arteries to the lower pole of the palatine tonsil, where the tract is eliminated and only the cyst or the remnant inferior tract persists. Recurrence rate depends upon completeness of resection (mean 5%). MALIGNANT TRANSFORMATION in the lining of a branchial cyst is detailed, but have demonstrably been nodal metastatic disease of an unknown primary (common sites of small occult primary tumour are tonsil, posterior tonsilllar pillar, retromolar tongue, nasopharynx) Branchial cysts, exceptionally commence within thyroid gland, the cystic residuum of the ultimobranchial body. Branchial cysts emanate within ectopic thyroid tissue and could build up to Papillary Carcinoma, thyroid. 33% of the cases with third branchial arch abnormality and 45% of the cases with fourth branchial arch abnormality proffer with acute infectious thyroiditis.

Figure 1: Squamous lining with germinal center