A case report of papillary adenocarcinoma in sublingual region--ultrastructural and histochemical study.

A rare case of papillary adenocarcinoma located in the sublingual region is presented. This case was initially considered to be a hemangioma and then the tentative clinical diagnosis was thyroglossal duct cyst at the time of the operation under general anesthesia. However, the final histopathologic diagnosis was papillary adenocarcinoma. We investigated its origin by histological, ultrastructural and histochemical techniques and it was suggested that this tumor arose from the minor salivary gland.