Metastatic chromophobe renal cell carcinoma in pleural fluid cytology: review of literature and report of a case.

The majority of chromophobe renal cell carcinomas (CHRCC) are not aggressive, however, a subset are. The potential for metastasis makes recognition of CHRCC cells in cytologic preparations important for patient surveillance, management, and treatment. We report the detection of an aggressive form of CHRCC in pleural fluid cytology with histopathologic confirmation on subsequent pleural biopsy. Sarcomatoid portions of the original CHRCC, and the pleural metastasis, demonstrated loss of diffuse membranous staining with C-KIT.