Branchial cyst | |
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Other names | Branchial arch fistula Benign cervical lymphoepithelial cyst Pharyngeal arch cyst |
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Fistulogram (sinogram) of a right branchial cleft sinus. | |
Specialty | Medical genetics ![]() |
Symptoms | Painless, firm mass lateral to midline, usually anterior to the SCM, which does not move with swallowing |
Causes | Family history |
Differential diagnosis | Vascular anomaly, dermoid cyst, thymic cyst, lymphadenopathy, lymphoma, HPV-related oropharyngeal cancer |
Treatment | Conservative, surgical excision |
A branchial cleft cyst or simply branchial cyst is a cyst as a swelling in the upper part of neck anterior to sternocleidomastoid. It can, but does not necessarily, have an opening to the skin surface, called a fistula. The cause is usually a developmental abnormality arising in the early prenatal period, typically failure of obliteration of the second, third, and fourth branchial cleft, i.e. failure of fusion of the second branchial arches and epicardial ridge in lower part of the neck. Branchial cleft cysts account for almost 20% of neck masses in children. [1] Less commonly, the cysts can develop from the first, third, or fourth clefts, and their location and the location of associated fistulas differs accordingly.
Most branchial cleft cysts present in late childhood or early adulthood as a solitary, painless mass, which went previously unnoticed, that has now become infected (typically after an upper respiratory tract infection). Fistulas, if present, are asymptomatic until infection arises. [2]
Branchial cleft cysts are remnants of embryonic development and result from a failure of obliteration of one of the branchial clefts, which are homologous to the structures in fish that develop into gills. [3] [4]
The cyst wall is composed of squamous epithelium (90%), columnar cells with or without cilia, or a mixture of both, with lymphoid infiltrate, often with prominent germinal centers and few subcapsular lymph sinuses. The cyst is typically surrounded by lymphoid tissue that has attenuated or absent overlying epithelium due to inflammatory changes. [5]
The diagnosis of branchial cleft cysts is typically done clinically due to their relatively consistent location in the neck, typically anterior to the sternocleidomastoid muscle. For masses presenting in adulthood, the presumption should be a malignancy until proven otherwise, since carcinomas of the tonsil, tongue base and thyroid may all present as cystic masses of the neck. [6] Unlike a thyroglossal duct cyst, when swallowing, the mass should not move up or down. [7]
Four branchial clefts (also called "grooves") form during the development of a human embryo. The first cleft normally develops into the external auditory canal, [8] but the remaining three arches are obliterated and have no persistent structures in normal development. Persistence or abnormal formation of these four clefts can all result in branchial cleft cysts which may or may not drain via sinus tracts.
Conservative (i.e. no treatment), or surgical excision. With surgical excision, recurrence is common, usually due to incomplete excision. Often, the tracts of the cyst will pass near important structures, such as the internal jugular vein, carotid artery, or facial nerve, making complete excision impractical due to the high risk of complications. [11]
An alternative and less invasive treatment is ultrasound-guided sclerotherapy. [12]
Articles related to anatomy include:
The brachiocephalic artery, brachiocephalic trunk, or innominate artery is an artery of the mediastinum that supplies blood to the right arm, head, and neck.
The external carotid artery is the major artery of the head and upper neck. It arises from the common carotid artery. It terminates by splitting into the superficial temporal and maxillary artery within the parotid gland.
A thyroglossal cyst or thyroglossal duct cyst is a fibrous cyst that forms from a persistent thyroglossal duct. Thyroglossal cysts can be defined as an irregular neck mass or a lump which develops from cells and tissues left over after the formation of the thyroid gland during developmental stages.
The jugular veins are veins that take blood from the head back to the heart via the superior vena cava. The internal jugular vein descends next to the internal carotid artery and continues posteriorly to the sternocleidomastoid muscle.
The internal jugular vein is a paired jugular vein that collects blood from the brain and the superficial parts of the face and neck. This vein runs in the carotid sheath with the common carotid artery and vagus nerve.
In anatomy, the left and right common carotid arteries (carotids) are arteries that supply the head and neck with oxygenated blood; they divide in the neck to form the external and internal carotid arteries.
The cavernous sinus within the human head is one of the dural venous sinuses creating a cavity called the lateral sellar compartment bordered by the temporal bone of the skull and the sphenoid bone, lateral to the sella turcica.
The superior thyroid artery arises from the external carotid artery just below the level of the greater cornu of the hyoid bone and ends in the thyroid gland.
The carotid triangle is a portion of the anterior triangle of the neck.
Cervical lymph nodes are lymph nodes found in the neck. Of the 800 lymph nodes in the human body, 300 are in the neck. Cervical lymph nodes are subject to a number of different pathological conditions including tumours, infection and inflammation.
A persistent thyroglossal duct is a usually benign medical condition in which the thyroglossal duct, a structure usually only found during embryonic development, fails to atrophy. The duct persists as a midline structure forming an open connection between the back of the tongue and the thyroid gland. This opening can lead to fluid accumulation and infection, which necessitate the removal of the duct.
The cervical sinus is a structure formed during embryonic development. It is a deep depression found on each side of the neck. It is formed as the second pharyngeal arch grows faster than the other pharyngeal arches, so they become covered. The first pharyngeal arch also grows slightly faster. It may fail to obliterate, forming a branchial cleft cyst or fistula, which is prone to infection.
The following outline is provided as an overview of and topical guide to human anatomy:
Preauricular sinuses and preauricular cysts are two common congenital malformations. Each involves the external ear. The difference between them is that a cyst does not connect with the skin, but a sinus does. Frequency of preauricular sinus differs depending the population: 0.1–0.9% in the US, 0.9% in the UK, and 4–10% in Asia and parts of Africa.
Congenital cartilaginous rest of the neck (CCRN) is a minor and very rare congenital cutaneous condition characterized by branchial arch remnants that are considered to be the cervical variant of accessory tragus. It resembles a rudimentary pinna that in most cases is located in the lower anterior part of the neck.
Ectopic thymus is a condition where thymus tissue is found in an abnormal location (ectopia). It usually does not cause symptoms, but may leads to a mass in the neck that may compress the trachea and the esophagus. It is thought to be the result of either a failure of descent or a failure of involution of normal thymus tissue. It may be diagnosed with radiology, such as an ultrasound or magnetic resonance imaging. If it causes illness, surgery can be used to remove it. Recurrence after surgery is very unlikely.
The cheek constitutes the facial periphery and plays a key role in the maintenance of oral competence and mastication. It is also involved in the facial manifestation of human emotion and supports neighboring primary structures.
Collaural fistula or cervico-aural fistula is a type of fistula whose openings are at external auditory canal and the neck, usually in the upper part of anterior border of sternocleidomastoid muscle. It occurs at birth because the defect is in the embryological branchial cleft. It is rare, and accounts for 8% of the branchial cleft anomalies, which is why it is sometimes misdiagnosed.
A cervical thymic cyst, also called thymopharyngeal duct cyst, is a fluid-filled mass that occurs when the thymopharyngeal duct, an embryonic structure connecting the nascent thymus with the embryonic pharynx, fails to close and disappear. A thymic cyst is typically a solitary mass on one side of the neck, and is usually found near the carotid sheath. Some cervical thymic cysts may extend into the mediastinum. It is usually asymptomatic. The diagnostic process includes differentiating between other causes of neck masses in infants and children, including branchial cleft cysts and cystic hygromas. The treatment is surgical excision. On histologic examination, the wall of the cyst includes thymic tissue, and may include parathyroid gland tissue because of the parathyroid gland's common embryonic origin with the thymus gland in the third pharyngeal pouch. Fewer than 100 cases of cervical thymic cysts have been reported in the medical literature.