Renal medullary carcinoma, a new clinico-pathological entity. Immunohistochemical, ultrastructural, flow cytometric and cytogenetic studies of one case

The renal medullary carcinoma is a rare tumor. We report a case in a black patient with sickle cell trait. The tumor was located in the lower pole of the left kidney. It had a tubular and microcystic architecture. Ir was comp osed of large eosinophilic cells with vesicular nuclei containing prominent nucleoli, irt a desmoplastic and inflammatory stroma. By immunohistochemis try, the tumoral cells were positive for cytokeratin and Ulex europaeus lec tin. Electron microscopy revealed small intracytoplasmic lumina with microv illi. The flow cytometric study showed DNA-multiploidy. The cytogenetic stu dy revealed tetraploidy without structural abnormality. The renal medullary carcinoma is often reported in young black patients with sickle cell trait . its microscopic, immunohistochemical and ultrastructural features favor i ts identification as a particular variety of Bellini duct carcinoma. Its li nk with sickle cell trait has to be defined.