[Sarcomatoid renal carcinoma]

Study of 250 pieces from nephrectomies performed in our service due to renal carcinoma, 10 (4%) of which where of the sarcomatoid histological variant. In 2 of the 10 cases, tumour was confined within the renal capsule at the time of surgery. These were the only cases where no disease progression was seen after treatment. A survival study using the Kaplan-Meter method was conducted. Median survival of patients with sarcomatoid pattern was 6 months, showing a significant difference with that obtained in other histological patterns. DNA content of tumoral cells was assessed by flow cytometry, which displayed a diploid pattern in 7 patients and aneuploid in 3. The 2 cases with no disease progression were diploid. We conducted nuclear cytomorphometry studies which showed significant differences in the mean nuclear perimeter between progressive and non-progressive tumours.