Abstract
Background : Collecting duct carcinoma of the kidney is a rare variant of renal cell carcinoma. Herein, we report the cytological findings of a case of collecting duct carcinoma of the kidney with extensive sarcomatoid change.
Case : A 50-year-old Japanese man visited a clinic for asymptomatic gross hematuria. Imaging examinations revealed a right renal tumor, and he was referred to our hospital. Calyceal lavage cytology revealed atypical glandular cells forming papillary structures, with vacuolated cytoplasm and eccentric nuclei. Under the clinical diagnosis of malignancy, right nephrectomy was performed. Imprint cytology of the right renal tumor revealed many tadpole-like cells and some sarcomatoid cells. Histology revealed collecting duct carcinoma with sarcomatoid change.
Conclusion : It is difficult to diagnose collecting duct carcinoma by urinary cytology alone. However, careful observation of the cytological specimens for the presence of both atypical glandular cells and sarcomatoid cells might lead to diagnosis of collecting duct carcinoma with sarcomatoid change.
