Primary sarcomas of the kidney. A clinicopathologic and DNA flow cytometric study of 17 cases.

Primary sarcomas of the kidney in adults are rare. In the handful of published reports of all soft tissue sarcomas, DNA ploidy has correlated with histologic grade and outcome. This report presents the clinicopathologic and flow cytometric features of 17 cases of primary renal sarcoma (seven men and ten women, ages 28-69 years). Presenting symptoms included abdominal and back pain and hematuria. Stages at diagnosis were I, in three patients; II, five patients; III, two patients; and IV, two patients. Eight tumors were leiomyosarcoma, two malignant fibrous histiocytoma, one hemangiopericytoma, one fibrosarcoma, and five unclassified. Tumors measured 5.5 to 23 cm, seven contained marked nuclear pleomorphism, seven were extensively necrotic, and mitotic rate was 1 to 33 per 10 high-power fields. Seven tumors showed aneuploidy and five were diploid. Thirteen patients were dead of disease after a mean of 23 months and two were alive with known metastases at 29 and 33 months, respectively. Ploidy pattern and outcome or time to death were not correlated, but aneuploidy correlated with histologic grade, marked nuclear pleomorphism (P less than 0.05), extensive necrosis (p less than 0.01), and high mitotic rate (0.05 less than P less than 0.10). The authors conclude that although DNA ploidy does correlate with histologic grade, for primary renal sarcomas, whose prognosis in this series was extremely poor, it does not correlate with outcome.