Malignant neuroendocrine tumor presenting in the mandible.

The carotid body, jugulotympanic, vagal, and laryngeal paragangliomas are the most common paragangliomas respectively within the head and neck, although unusual examples in other sites have been described. Among these are several references in the literature to a mandibular or "alveolar body" paraganglioma, even though such an entity does not appear to have been adequately documented. This report describes a case which presented as an extensive osteoblastic tumor involving the mandible and which radiographically appeared as a typical osteosarcoma. However, the immunohistochemical and electron microscopic features were of a neuroendocrine tumor and the histologic pattern suggested a paraganglioma. The tumor was nonfunctional and an extensive search failed to reveal any further lesions. Eight months after resection of the lesion, metastatic deposits appeared within the left iliac crest and lumbar vertebra. The origin of this tumor is discussed.