Fig. 1

CT imaging of the patient and macroscopic and histopathological analysis of the kidney tumor tissue a CT scan of the abdomen shows massive enlarged kidneys with bilateral tumorous lesions. b and c CT scan of the thorax reveals numerous pulmonary cysts (b, red arrows) and several pulmonary lesions suspicious for metastastic disease (c, red arrow). d Macroscopic picture of the left kidney shows that the whole organ is interspersed with nodular tumors. e Beside the nodular growing chromophobe carcinoma (right side) a second tumor component consisting of very small tumor cells can be detected (left side of the panel, bar = 100 μm). f these small tumors cells show nuclear pleomorphism with increased and atypical mitosis (bar = 50 μm)