Cytohistological study of clear cell carcinoma of kidney with special reference to nuclear grading and tumor size.

Several prognostic indicators have shown to predict patients' survival in clear cell carcinoma of kidney. Among these, Fuhrman nuclear grading and tumor size are believed to be two important prognostic factors. The aim of this study was to evaluate the efficacy of fine needle aspiration cytology (FNAC) to classify the clear cell renal cell carcinoma (CRCC) according to nuclear grade and tumor size. A total of 24 patients (15 males, 9 females) suffering from CRCC were included in this study over a period of 5 years (January, 2005 to December, 2009). A preoperative cytologic diagnosis was made by computed tomography guided FNAC and histologic correlation was made after surgery. Cytologic diagnoses were nuclear grade 1 or G1 (four cases), nuclear grade 2 or G2 (11 cases), nuclear grade 3 or G3 (six cases) and nuclear grade 4 or G4 (three cases). Radical nephrectomies were done during surgery and most of the specimens were from right side (18/24). Upper pole was commonly involved by the tumor (19/24). Low nuclear grade lesions (G1 and G2) were commonly seen with tumor size up to 5 cm and high nuclear grade lesions (G3 and G4) were common when tumor was >5 cm in size. After cytohistologic correlation, diagnostic accuracy of FNAC was found to be 87.5% in this study. FNAC has high diagnostic accuracy in CRCC and highly dependable procedure to classify these tumors according to its nuclear grade. Both the nuclear grading and tumor size can be used to predict the clinical outcome in these patients.