BACKGROUND: Chromophobe renal cell carcinoma (ChRCC) is a morphologically distinct renal cell carcinoma type which may rarely show composite morphology.CASE: A 61-year-old man presented with a composite ChRCC with sarcomatoid transformation containing osteosarcomatous, chondrosarcomatous and squamous metaplastic differentiation and associated with a high-grade collecting duct carcinoma (CDC). The patient presented with a metastatic disease in the regional lymph nodes, comprised only of CDC, and died after 21 months.CONCLUSION: Although ChRCC associated with sarcomatoid change has been well documented, the presence of osteosarcoma has been previously reported in only 5 ChRCCs, 2 of which also contained chondrosarcoma. Squamous differentiation has been previously found in only 2 ChRCCs with sarcomatoid change, and ChRCC associated with CDC has been previously reported in only 3 cases, but none with heterologous elements. To our knowledge this represents a previously unreported composite type of RCC, with an aggressive clinical behavior.
Carcinoma, Renal Cell Chondrosarcoma