An unusual abnormality, glomus tumor (glomangioma) develops as a small painful unencapsulated nodule as a result of hamartomatous proliferation of the modiļ¬ed smooth-muscle pericytic cells found in the characteristic type of peripheral arteriovenous anastomosis known as the glomus.
In addition to having a characteristic histology, these lesions also may secrete various catecholamines. The glomus tumor is rare in the mouth but can occur in the pterygotemporotympanic region,glomus jugulare, and skull base. Glomus tumors arising in the carotid and aortic bodies may produce neck masses; they are of a different cell derivation (ie, chemosensory) and are more appropriately referred to as chemodectomas or paragangliomas. Differentiation of the glomus tumor from other masses of proliferating vascular endothelial cells (hemangioendothelioma and hemangiopericytoma) requires special stains and considerable histopathologic diagnostic skills. Another important diagnostic feature that characterizes at least some glomus tumors is an autosomal dominant inheritance pattern. Because of the associated pain, glomus tumors tend to be removed while still quite small.