This document presents a case study of a 23-year-old patient who presented with a right neck cyst. Imaging including ultrasound, CT, and MRI revealed a cystic mass posterior to the mandibular ramus. Differential diagnoses included thyroglossal duct cyst, cystic hygroma/lymphangioma, and dermoid cyst. However, based on location and imaging features such as extension between the carotid arteries, it was determined to be a second branchial cleft cyst. The document discusses branchial arch embryology and anomalies that can result from incomplete obliteration of clefts, including branchial cysts. Branchial cysts most commonly involve the second arch and present as painless swellings in
24. Branchial CystTypes
• Type I superficial
anterior surface of
sternocleidomastoid
• Type II
posterior to the submandibular
gland
• Type III lateral to the pharyngeal wall.
• Type IV- deep to the carotid sheath
29. CT
rounded or spheric, sharply circumscribed
fluid density centrally
thin wall
extension of the cyst wall between the internal and
external carotid arteries just above the carotid bifurcation
(features referred to as the notch sign, tail sign or beak
sign ), is highly suggestive of the diagnosis but not
pathognomonic
Radiographic Features