Five Cases of Adenocarcinoma in the Parasinuses

We encountered 5 Japanese patients with adenocarcinoma of the parasinuses. Histologic findings were adenoid cystic carcinoma, mucoepidermoid carcinoma (56 year-old, male; 48 year-old, female; 44 year-old, female; 57 year-old, male) and adenoacanthoma (64 year-old, female).Adenoid cystic carcinoma and mucoepidermoid carcinoma originated in the submucosal mucous gland and had a similar appearance to those which originated in the salivary gland. Occasionally a transitional pattern can be identified.Mucoepidermoid carcinoma originated in the main duct and adenoid cystic carcinoma stemmed from the peripheral duct near the acinal gland.Most of the carcinomas were derived from the columnal epithelium and were a squamous cell carcinoma due to metaplasia. However, adenocarcinoma or adenoacanthoma derived from the lining epithelium was also occasionally seen.Surgical treatment was carried out as the response to radiotherapy was poor. Post-operatively all patients did well. As macroscopic observations are often misleading, the area to be excised should be biopsied and the frozen sections carefully examined.