RADIOLOGY: NECK: Case# 33049: NECK MASS. A 25-year-old female being evaluated for a submandibular mass which has been present for the past 1.5 years and is slowly growing. 1. With the patients history of a slowly growing (1.5 years) mass within the submandibular region, primary differential considerations include a epidermoid/dermoid, unilocular cystic hygroma, or a diving ranula. Also (given the young age of the patient) a second branchial cleft anomaly is another consideration. Does the patient have a sinus tract or fistula present above the clavicle to support the latter suspicion? An infection is considered, but is far less likely due to the lack of inflammatory changes and enhancement; additionally, adenopathy is not identified. A malignant process is also considered unikely considering the age of the patient and the fluid density of the lesion. 2. Paranasal sinus disease as described above.