口底に発生した明細胞腫の１例とその組織化学的および免疫組織化学的検討

Abstract

A tumor consisting of clear cells such as in the case of clear cell carcinoma of the kidney is often seen in nearly any organ. However this occurs quite rarely in the salivary gland. We examined the histochemical and immunohistochemical distribution of clear cell tumor in the oral floor of a 74 year-old female. The tumor consisted of clear cells with heterogeneity and showing a mixture of bimorphic patterns with glandular elements containing an inner layer having eosinophilic large cells, an outer layer of clear cells and monotonous proliferation of clear cells in some portions. These clear cells contained cytoplasmic glycogen as PAS positive granules. Positive results were obtained for keratin, EMA, vimentin, S-100 protein, actin and myosin by immunohistochemical examination of the tumor cells. This tumor thus originated from multipotential cells capable of differentiating into both glandular epithelial and myoepithelial cells. This tumor appeared biologically to be at least a low-grade malignancy. After a follow-up of 2 years and months following extirpation of the tumor, the patient showed no symptoms.