Branchial Cleft Fistula
- A congenital, abnormal tract connecting the skin of the neck with an internal structure
- Results from the incomplete closure or development of the branchial arches or associated clefts
- Involves branchial clefts I to IV, which develop in the 4th week of gestation
- System(s) affected: skin/exocrine
Most occur in the pediatric age group; the second most common congenital neck masses (20–30%) and the most common lateral neck masses (Thyroglossal duct anomalies are the most common overall and midline.) (1)
- Predominant age: By definition, all branchial cleft fistulae are present at birth; however, they may remain unnoticed for some time.
- Often present when the cyst becomes acutely inflamed or infected
- Branchial cleft cysts may not present until adulthood and are commonly diagnosed in the 3rd and 5th decades of life.
- Predominant sex: male = female
Etiology and Pathophysiology
- Branchial anomalies result from the incomplete obliteration of pharyngeal clefts and pouches during embryogenesis.
- Both respiratory and squamous epithelium (alone or together) may line branchial anomalies.
- Squamous epithelium is found more commonly in cysts.
- Ciliated, columnar epithelium is found more commonly in sinuses and fistulae.
- The first branchial cleft contributes to the external auditory canal, middle ear cavity, mastoid air cells, and eustachian tube. Related fistulae are very rare and tend to be infra- or retroauricular. Preauricular cysts and sinuses are not thought to be of branchial cleft origin:
- First branchial cleft anomalies enter the external auditory canal and/or occasionally the middle ear.
- They represent approximately 1–5% of all branchial cleft malformations.
- Type I anomalies contain ectodermal elements only and course lateral to the facial nerve and parotid gland.
- Type II anomalies contain ectoderm and mesoderm, coursing medial to the facial nerve often inferior to the angle of the mandible.
- The second branchial cleft forms the hyoid bone and tonsillar fossa. Related fistulas (most common variant) course between the internal and external carotid arteries:
- Second branchial anomalies represent up to 95% of all branchial cleft lesions. Up to 10% of presentations are bilateral (2).
- They course close to the glossopharyngeal and hypoglossal nerves, entering the pharynx at the level of supratonsillar fossa.
- The external opening runs inferior to the angle of the mandible and along anterior border of sternocleidomastoid (SCM) muscle.
- Second branchial cleft anomalies are subdivided into four subtypes:
- Type I lesions are anterior to the SCM and do not involve the carotid sheath.
- Type II lesions are the most common second branchial cleft anomalies, deep to the SCM, and anterior or posterior to the carotid artery.
- Type III lesions pass between the internal and external carotid arteries and are adjacent to the pharynx.
- Type IV lesions are medial to the sheath, adjacent to the tonsillar fossa.
- The third and fourth branchial clefts form the parathyroid glands, thymus, and portions of thyroid gland (parafollicular cells):
- Third branchial cleft anomalies represent approximately 1% of all branchial anomalies. Fourth branchial cleft anomalies are quite rare (<1%).
- Sinus tracts (also called pyriform sinuses) originate in the pyriform sinus and course adjacent to the thyroid cartilage.
- Fistulas are rare, usually resulting from recurrent infections and/or repeated surgery.
- Both third and fourth fistulas should have external ostia on the lower anterior neck. Left-sided lesions are more common than right-sided ones.
- They are often called pyriform sinus “fistulae,” despite the frequent lack of an external opening to the skin.
- Those from the third branchial cleft course posterior to carotid artery.
- Differentiated from second branchial cleft anomalies by the location of their internal opening (external openings should be the same)
- Presence of thymic tissue does not differentiate between third and fourth branchial cleft anomalies because accessory thymic tissue has been described in the latter (3).
10% have family history.
Positive family history
Commonly Associated Conditions
- Microtia and aural atresia occur with failure of development of the first branchial cleft.
- The rare constellation of second branchial arch anomalies; malformations of the outer, middle, and inner ear associated with sensorineural; mixed or conductive hearing loss, and the absence of renal abnormalities is known as branchiootic syndrome.
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