Primary Carcinoid Tumor of the Parotid Gland: A Case Report and Review of the Literature

Abstract

Salivary gland tumors account for 3 to 6% of all head and neck neoplasms in adults. Some 70 to 85% of these lesions are found in the parotid. Carcinoid tumors, which represent a distinct and relatively uncommon subset of neuroendocrine tumors, are most commonly found in the gastrointestinal tract, although in rare cases they are known to occur in extragastrointestinal locations, including the larynx, middle ear, and pancreas. Malignancies of the parotid gland are uncommon (approximately 25% of parotid neoplasms), and to the best of our knowledge, a primary carcinoid tumor of the parotid has not been previously described in the literature. Reports of parotid carcinoid tumors during the past 30 years have described the presence of nonparotid primary carcinoid tumors (usually gastrointestinal) that had been diagnosed and treated several years prior to the presentation of the parotid lesion. Under such circumstances, the parotid lesion may be assumed to have been a metastatic rather than a primary carcinoid. This report documents what we believe is the first case of a primary carcinoid tumor of the parotid gland. We detail the clinical, surgical, radiologic, immunologic, and histochemical findings associated with its diagnosis, and we describe our management of this case. Although a primary carcinoid in this location is exquisitely rare, knowledge of such lesions is important because their management is substantially different from that of other parotid tumors. In particular, it is important to differentiate them from metastatic tumors from other sites.