Tubulocystic carcinoma of kidney associated with papillary renal cell carcinoma.

Tubulocystic renal cell carcinoma (TCRCC) is a rare variant of renal cell carcinoma, which has distinct histology but there is some controversy about its association with papillary renal cell carcinoma (PRCC) and cell of origin in literature. We report an 18-year-old girl with the rare TCRCC of kidney associated with PRCC with metastases to the para-aortic nodes. The patient presented with hematuria and a right renal mass with enlarged regional nodes for which a radical nephrectomy with retroperitoneal lymph node dissection was done. On gross examination, a solid cystic lesion involving the lower pole and middle pole of the kidney measuring 12x9x9 cm was seen along with an additional cystic lesion in upper pole of kidney. Microscopically the main tumor showed the typical histology of a tubulocystic carcinoma with multiple cysts filled with secretions lined by variably flattened epithelium with hobnailing of cells. The mass in the upper pole was a high-grade PRCC and the nodal metastases had morphology similar to this component. To conclude, at least a small but definite subset of TCRCC is associated with PRCC, and cases associated with PRCC do seem to have a higher propensity for nodal metastasis as in the case we report.