Abnormal venous structures in salivary gland tumors: vasculature characteristics of pleomorphic adenoma
Abstract:To clarify the diagnostic significance of abnormal venous structures present in salivary gland tumors, we examined 21 pleomorphic adenomas, 14 Warthin tumors, 1 oncocytic adenoma, 3 myoepitheliomas, 7 basal cell adenomas, 5 mucoepidermoid carcinomas, and 6 adenoid cystic carcinomas. Verhoeff-van Gieson staining was carried out and the morphology of the veins within the tumors was observed microscopically. Branching veins, thickened intima of the veins, discontinuous elastic membrane and multilayered elastic membrane were seen in 71.4%, 76.2%, 47.6% and 85.7% of pleomorphic adenomas, respectively, and were abundant and easily found in most cases. The abnormal venous structures were also found in other salivary gland tumors examined, but they were few in number and lacked variety. Elastic fibers extending radially into the surrounding stroma were seen in 66.7% of pleomorphic adenomas, and were not seen in other salivary gland tumors. Our results showed that a variety of abnormal venous structures are more abundant and more easily found in pleomorphic adenoma compared with other salivary gland tumors, and, in particular, that perivascular radiating elastic fibers are characteristic of pleomorphic adenoma. We emphasize that the presence of perivascular radiating elastic fibers may be helpful in diagnosing pleomorphic adenoma in small biopsy specimens.
Document Type: Original Article
Publication date: September 1, 2001