A 25 year-old male presented with a tender, fixed 3-cm right parotid mass persisting over 2 years with recent interval enlargement. CT scan demonstrated a cystic mass that did not invade adjacent soft tissue or bone. Fine needle aspiration (FNA) yielded cyst fluid. Total parotidectomy with facial nerve dissection for a presumed parotid tumor demonstrated a mass tracking deep to the facial nerve, coursing medially and superiorly to terminate adjacent to the cartilaginous external auditory canal (EAC). Pathology revealed an epithelial-lined cyst with hair matrix surrounded by elastic cartilage in focal areas consistent with a Work type II first branchial cleft cyst with EAC duplication.
This case supports the literature in demonstrating that 1. misdiagnosis occurs commonly and frequently necessitates revision; 2. full facial nerve dissection reduces incidence of its injury; and 3. increased familiarity with its clinical symptoms, inclusion on the differential for parotid masses, preoperative imaging, and identification of a tract in the specimen can reduce recurrence rates. Work type II first branchial cleft anomalies must be included in the differential diagnosis for head and neck masses above the level of the hyoid bone. Preoperative imaging, more so than FNA, can confirm the diagnosis. Improved diagnosis can ensure the appropriate surgical approach, and decrease the risk of post-operative complications.
Mal-development of First Branchial Cleft Leads to External
Auditory Canal Malformations 2