Low-grade renal cell carcinoma. A clinicopathologic study of 53 cases

Fifty-three low-grade renal cell carcinomas and oncocytomas were reviewed to assess the prognostic significance of nuclear grade (grade 1 versus grade 2), character of cell cytoplasm, size, and stage. Twelve of 46 patients (27%) with follow-up died of disease. Stage 4 disease (most often, extensive local spread) best predicted decreased survival. The survival of patients with stage 1, 2, and 3 tumors was similar; and renal vein invasion was not an adverse prognostic indicator. Size also appeared to predict patient survival; tumors greater than 10 cm metastasized at a higher rate than neoplasms 5 cm or less. We were unable to demonstrate statistically significant differences in survival between individuals with grade 1 and 2 neoplasms, nor were we able to demonstrate a statistically significant difference in survival on the basis of the character of the cell cytoplasm. However, there was a trend toward better survival for patients with granular cell carcinomas and oncocytomas as opposed to neoplasms with clear or mixed cell cytoplasm. Although the number of patients with granular cell carcinomas and oncocytomas is small, the data suggest that the distinction between low-grade granular cell carcinomas and oncocytomas adds little prognostic information.