UroToday- The most common histologic subtype of renal cell carcinoma (RCC) is clear cell, which represents the overwhelming majority of cases. Because of the relative rarity of the other histologic subtypes (papillary, chromophobe, translocation, unclassified, collecting duct, etc.) less is known about their clinical behavior and patient outcome following therapy. In general, non-clear cell histology portends an improved prognosis when the tumor is localized and a worse prognosis when the tumor is metastatic. Here, Pignot and colleagues report on the significance of histologic subtyping of papillary RCC as it impacts patient outcome.

Over a 9 year period, the authors treated 130 patients with papillary RCC. Mean patient age was 60.6, median tumor size was 4.5 cm (range 0.5-21 cm), 78.4% of patients were treated with radical nephrectomy, and the median follow-up was 48 months. The tumor presented as an incidental finding in 66%, 3% were bilateral, and 4.6% were multifocal. Type I papillary histology was noted in 52.3% and Type II was noted in 47.7%. Type II histology was associated with increased tumor stage, grade, and increased incidence of microvascular invasion (p