Renal Mucinous Tubular and Spindle Cell Carcinoma
Renal cell tumor characterized by tubular formations merging with bland spindle cells in a myxoid stroma.
This tumor accounts for less than 1% of all renal neoplasms.
It arises during the sixth decade of live.
There is a female predilection (M:F = 1:3).
There is no site predilection.
Partial or radical nephrectomy is the treatment of choice.
Only rare cases have metastasized to lymph nodes and have shown sarcomatoid dedifferentiation.
The tumor is solid, pale tan to yellow that may have slight focal areas of necrosis or hemorrhage.
The neoplastic cells are generally positive for CK7 and AMACR.
Data regarding mucinous tubular and spindle cell carcinoma indicate various chromosomal losses and gains but no loss of 3p or trisomy 7 and/or trisomy 17 (Cossu-Rocca et al. 2006).
Papillary renal cell carcinoma is the most important differential diagnosis. Due to the overlapping immunophenotype, FISH analysis is the most reliable tool in the routine diagnostic workup.