Carcinoma de células claras variedad no hialinizante de parótida: Comunicación de dos casos con diferente grado de diferenciación

Abstract

The clear cell carcinoma is a rare neoplam of low level grade that develops almost exclusively in human minor salivary glands. The objective of this present work is to analyze the structural, histochemical and inmunohistochemical (IHQ) characteristics of two cases of parotid clear cell carcinoma and make a differential diagnosis with other primary and metastatic salivary tumors that clear cells show. Serial cuts of both tumors were processed for H/E, Masson and Dane trichromes, Toluidine blue, Alcian blue, PAS and PAS/diastase; IHQ marking of both high-and low-molecular weight cytokeratins, ki67, HMB45, p63 and S-100 protein. The structural pattern of these tumors were determined by nests and cords of clear cells delimited by a stroma non hyaline. In a tumor a malign neoplasia was observed in clear cells with anaplasia. The ki67 expression was important. The other tumor was constitued of clear monomorph cells without manifestation signs of atypia and almost no ki67 expression. With PAS was confirmed the presence of glycogen and not observed an important development of the collagen stroma in both neoplasms. Both cases resulted very positive the immunostaining of both high and low molecular weight cytokeratins. It resulted negative for the HMB45 and p63. The protein S-100 has it's expression in isolated cells. We conclude that: the presented cases are very uncommon localization (parotid) as described by the literature; it matches a non hyalinizing variety because a very important hyalinized collagen stroma is not present, both primary tumors of salivary glands, of epithelial origin, non melanocytic, renal or hematopoietic lymphomas which shows immunostaining IHQ.