Branchial cleft anomalies: a pictorial review of embryological development and spectrum of imaging findings

Abstract

The branchial arches are the embryological precursors of the face, neck and pharynx. Anomalies of the branchial arches are the second most common congenital lesions of the head and neck in children, with second branchial arch anomalies by far the most common. Clinically, these congenital anomalies may present as cysts, sinus tracts, fistulae or cartilaginous remnants with typical clinical and radiological findings. We review the normal embryological development of the branchial arches and the anatomical structures of the head and neck that derive from each arch. The typical clinical and radiological appearances of both common and uncommon branchial arch abnormalities are discussed with an emphasis on branchial cleft anomalies.Key points• Anomalies of the branchial arches usually present as cysts, sinuses or fistulae.• Second branchial arch anomalies account for approximately 95 % of cases.• There are no pathognomonic imaging features so diagnosis depends on a high index of suspicion and knowledge of typical locations.• Persistent cysts, fistulae or recurrent localised infection may be due to branchial arch anomalies.• Surgical excision of the cyst or tract is the most common curative option.

MRI Sequences in Head & Neck Radiology – State of the Art

“…These features are important in the diagnosis of deep neck abscesses such as in the retropharyngeal space [3]. Congenital lesions such as thyreoglossal duct remnants and anomalies of the branchial arches typically presenting as cysts, sinus tracts, fistulae or cartilaginous remnants may be diagnosed based on location, clinical symptoms and MRI findings [4]. Lesions of the salivary glands or stone-related pathologies can be clearly depicted.…”

“…cysts, sinus tracts, fistulae or cartilaginous remnants based on location and clinical symptoms [4] sinonasal inverted papilloma convoluted cerebriform pattern on T2w and T1wC+ [6] paraganglioma "salt and pepper" appearance (30 -40 %) [7] cancer intermediate to high signal in T2w, high signal in T1wC+, mass, infiltration, inhomogeneity, necrosis perineural invasion T2w and T1w thickening and T1wC+ contrast enhancement along the cranial nerve [8] dural invasion nodular dural enhancement on T1wC+ and width of enhancement of more than 5 mm [9] mandibular bone invasion replacement of peripheral hypointense signal (cortical bone) through either tumor signal intensity on both T1w and T2w, or central hyperintense signal (medullary bone) is replaced by intermediate tumor signal [11] neoplastic invasion of laryngeal cartilages low T1w signal, similar to that of tumor T2w signal and similar to tumor T1wC+ signal [12] residual cancer after chemoradiation therapy intermediate T2 signal intensity similar to that of the untreated tumor with areas formed a focal expansible mass > = 1 cm [14] dissection high T1w signal in the vessel wall [15] TIRM/STIR, Dixon, spectral fat sat edema, swelling, tumor high signal in TIRM/STIR necrosis, cystic lesions high signal in TIRM/STIR adipose tissue (lipoma, cholesterol granuloma) suppressed signal lymph node metastasis nodal size (minimum axial diameter of 8 -9 mm in level II and 7 -8 mm for the rest of the neck), loss of hilar structure and necrosis (varying level of low-to-high signal intensity on T2w fat sat depending on keratinization, and coagulation and liquefaction necrosis) [18]; lower signal than regular or reactive lymph nodes on inverted TIRM/ STIR [16] extranodal tumor spread nodal size, shaggy margin and flare sign on T2w fat sat [19] SSFP (CISS, FIESTA), SPACE, VISTA, 3D-FLAIR cerebellopontine angles and inner ear (facial and vestibulocochlear nerves, schwannomas)…”

Branchial fistula: review of literature and case report

“…They are the second most common congenital lesions of head and neck in children and account for approximately 17% of all paediatric cervical masses. [1][2][3] The branchial arches develop in the fourth week of gestation and are the embryological precursors of ear and muscles, blood vessels, bones, cartilage and mucosal lining of the face, neck and pharynx. In total, six pairs of branchial arches are formed on either side of the pharyngeal foregut in cranio-caudal succession.…”

“…The fifth pharyngeal arch is usually rudimentary, or disappears and the sixth arch is often represented as part of the fourth arch due to its small size. [2][3][4] Thus, depending on the anatomic location, branchial anomalies have been classified into first, second, third and fourth arch anomalies. Second branchial arch anomalies are the most common accounting for approximately 95% of cases.…”

“…First branchial arch anomalies account for 1-4% cases; third and fourth branchial arch anomalies are extremely rare. [2][3][4][5] They may present as cysts, sinus tracts, fistulae or cartilaginous remnants. Cysts are the entrapped remnants of branchial clefts; sinuses are remnants of clefts or pouches; and fistulae can result from persistence of both pouch and cleft.…”