Fig. 4From: Erythrocytosis caused by giant chromophobe renal cell carcinoma: a case report indicating a 9-year misdiagnosis of polycythemia veraImmunohistochemical examination of the tumor with specific antibodies. Immunohistochemical staining of the tumor section shows a strong positivity for cytokeratin 7 in both the cytoplasm and membrane, b negative Vimentin expression, c negative CD10 expression in both the cytoplasm and membrane, and d middle to strong positivity for erythropoietin (EPO) in the cytoplasm. The results confirmed the diagnosis of chromophobe renal cell carcinoma and EPO production of the tumorBack to article page