Characterizing Adenoid Cystic Carcinoma of the Middle Ear-A Rare Entity.

Objectives: To characterize patient demographics, tumor features, treatment patterns, and survival outcomes of adenoid cystic carcinoma of the middle ear.

Methods: Retrospective review of the Surveillance, Epidemiology, and End Results Database of the National Cancer Institute for all cases of histopathologically confirmed adenoid cystic carcinoma of the middle ear as the primary location.

Results: Twenty-one patients with adenoid cystic carcinoma of the middle ear were identified. Patients had a median age of 61 years (range 16-86) and were more commonly female (57.1%) and Caucasian (85.7%). Tumors had a median size of 11 mm (range 5-22) with disease involvement most frequently locally (70%), followed by distant (20%), then regional disease (10%). Most underwent upfront surgery (85.7%) compared to radiation therapy (14.3%). Surgery was often followed by radiation. Five- and ten-year disease-specific survival remained stable at 67.3%.

Conclusion: Demographics of middle ear adenoid cystic carcinoma reflect that of other primary locations, with a predilection for middle-aged and female patients. Tumors more often present with local involvement, though distant metastasis is not uncommon. Surgery, followed by radiation, appears to be the favored treatment modality and generally portends a good prognosis, despite involvement of a complicated anatomic location. Further research is necessary to better characterize the disease and define its optimal management.

Level of evidence: 4: