2003 年 42 巻 3 号 p. 260-261
We encountered a case of renal oncocytoma which was difficult to distinguish from renal cell carcinoma with an intraoperative frozen section, but differential diagnosis was possible with an imprint cytology specimen. The tumor cells represened moderately plcomorphic and polygonal nuclei in the frozen section. Imprint cytology, however, did not show such atypia of tumor cells. The reason for the discrepancy of tumor cells morphology between both specimens seems to be derived from the difference in the methods of specimen preparation: morphology in the frozen section tends to be artificially influenced by water contained in the tissue. On the other hand, the imprint cytology specimen seems to keep the original histological features more faithfully. Thus, this case would appear to suggest the importance of imprint cytology for the intraoperative diagnosis of renal cell tumors.