A Pediatric Radiology Textbook and Pediatric Radiology Digital Library
Second Branchial Cleft Cyst
Etiology: — Remnant of embryonal branchial arch incompletely obliterated — Courses from posterior to submandibular gland and anteromedial to sternocleidomastoid muscle and lateral to carotid space
Imaging: — Usually occur at angle of mandible — Look between sternocleidomastoid muscle and submandibular gland for fistula from palatine fossa which leads to skin anterior to sternocleidomastoid muscle in supraclavicular region
Imaging US: Internal debris may look more solid
Imaging CT: — Low density — Notch sign (cyst extension between internal carotid artery and external carotid artery bifurcation) — If it has thick wall or contrast enhancement think infection
Imaging MRI: — T1WI: Hypointense — T1WI post contrast: No enhancement — T2WI: Hyperintense
DDX:
Complications: Infection
Treatment:
Clinical: — 90% of branchial cleft cysts — Presents as painless angle of mandible mass but can be painful if infected — With unexplained abscess in the neck look for branchial cleft anomaly
Radiology Cases of Second Branchial Cleft Cyst
Axial (left) CT with contrast of the neck shows a round, low density mass on the right with rim enhancement anterior to the right sternocleidomastoid muscle and inferior to the angle of the mandible and posterior to the right submandibular gland that has a sinus tract to the skin best seen on the coronal CT (right).Axial (above), coronal (below left), and sagittal (below right) CT with contrast of the neck show a thin walled low density mass anterior to the left sternocleidomastoid muscle and posterior to the left submandibular gland. Superiorly the mass goes to the angle of the mandible and inferiorly the mass goes to the hyoid bone.
Clinical Cases of Second Branchial Cleft Cyst
Clinical images show a punctate cyst at the anterior border of the right sternocleidomastoid muscle (above) that with some massaging is seen to emit fluid (below).
Surgery Cases of Second Branchial Cleft Cyst
Surgical image shows excision of the sinus up to its origin in the tonsillar fossa with a probe inserted into the lumen of the sinus tract.
Histopathology Cases of Second Branchial Cleft Cyst
Histopathological image H&E stained section shows a fibrous walled cyst lined by ciliated, respiratory-type epithelium.Histopathological image H&E stained section shows the sinus tract through skeletal muscle.
