Terminal duct carcinoma. Recognition of a low-grade salivary adenocarcinoma

We describe six cases of terminal duct carcinoma of the minor salivary glands. All were localized to the oral cavity, without regional nodal or distant metastases. Histologically, five were originally mistaken for adenoid cystic carcinoma; one was interpreted as monomorphic adenoma with areas of adenoid cystic carcinoma. Treatment consisted of wide resection with or without radiation therapy, with no incidence of recurrence or metastasis. The characteristics of this recently described pathologic entity are reviewed. The less aggressive behavior of this tumor compared with adenoid cystic carcinoma should call for less radical therapy, with a favorable prognosis in most cases. Recognition of this tumor as a distinct clinical and pathologic entity is therefore important.