Primary carcinoid tumors of the middle ear. Report on four cases and a review of the literature.

Carcinoid tumors are rare in the middle ear. To our knowledge, only 17 cases could be found in the literature, the first of which was described in 1980. In addition to enlarging on a previous observation we present three new cases. The neoplasms showed a striking, heterogeneous aspect ranging from solid trabecular to tubuloglandular growth patterns resembling the classic carcinoid tumor and adenomatous middle ear tumor, respectively. Based on immunohistochemistry and electron microscopy, three cell types were found. A review was made of our four patients and the cases described in the literature. The medical histories ranged from 1 month to 9 years. Presenting symptoms and signs were not characteristics, but hearing loss predominated. In two patients, the eardrums were perforated, in all the others it was intact and often bulging. Surgery, usually radical mastoidectomy, was performed in all cases. Often the tumor encased the ossicular chain, without infiltration. In two patients, local recurrence occurred that was treated successfully with surgery. All the cases showed an indolent biological course and the tumors were clinically nonfunctional, despite the recognition of biogenically active products by immunohistochemistry. To our knowledge, regional or distant metastases have never been reported. Conservative surgery with radical removal of the primary or recurrent tumor is the treatment of choice.