SALIVARY DUCT CARCINOMA - A CLINICOPATHOLOGICAL STUDY OF 3 CASES WITHA REVIEW OF THE LITERATURE

Three cases of salivary duct carcinoma are presented, They occurred in a 60 year old man, a 66 year old man and a 57 year old woman, All of the lesions were located in the parotid gland, The tumor size ranged f rom 3 to 5 cm across the largest diameter, Facial paralysis was observ ed in two cases, Histologically, intraductal and invasive adenocarcino ma showing papillary, cribriform, and solid patterns with comedo-like necrosis was observed. Immunohistochemically, the tumor cells were pos itive for keratin and epithelial membrane antigen. No myoepithelial ce lls were demonstrated within the tumor by staining for S-100 protein, alpha-smooth muscle actin or muscle specific actin, Ultrastructurally, intracytoplasmic lumina with microvilli, a moderate number of mitochr ondria, lysosomes, and tight junctions were found. Regional lymph node metastasis was observed in one case, and distant metastasis developed in two cases, All of the patients were treated with adjuvant postoper ative irradiation. One patient died of disease at 11 months after the initial diagnosis, another was alive with disease at 8 months, and the third patient was alive without disease at 2 years and 3 months, Sali vary duct carcinoma should be differentiated from low-grade salivary g land carcinomas using morphologic and clinical criteria because of its poor prognosis even with aggressive therapy.