Evaluation of Nuclear Morphometry and Ki-67 Index in Clear Cell Renal Cell Carcinomas: a Five-Year Study

BACKGROUND AND OBJECTIVE: Clear Cell Renal Cell Carcinoma (CCRCC) is the most common adult renal neoplasm. Staging and grading of RCC are important predictors of survival. Fuhrman nuclear grading is widely used for CCRCC, the subjective nature of which has prompted more objective methods to evaluate nuclear features. Furthermore, Ki-67, a reliable marker of cellular proliferation may provide another variable for assessment of the biological behavior of RCC. The aim of this research was to study nuclear morphometry and Fuhrman nuclear grading of clear cell RCC, and to assess their relationship with the Ki-67 index. METHODS: Hematoxylin and eosin slides of forty cases of CCRCC were retrieved and studied for pathologic variables, including Fuhrman nuclear grade, pathological tumor and node stage. Nuclear morphometric analysis was performed using computer-assisted image analysis. The relationship between Fuhrman nuclear grading, pathologic stage, tumor size, nuclear morphometry and proliferative index were analyzed. RESULTS: According to Fuhrman grading, four (10%) cases were grade I, 23 (57.5%) were grade II, 12 (30%) were grade III, and one (2.5%) was grade IV. Moderate to high correlation was seen between Fuhrman nuclear grade and mean nuclear area, perimeter, diameter, length, nuclear roundness factor and Ki -67, with a P value of < 0.05. CONCLUSION: The CCRCC is an extremely heterogenous disease and clinical outcome is unpredictable despite several validated prognostic factors. The widely used Fuhrman nuclear grading is subjective, while nuclear morphometry, using computer assisted image analysis, can ensure more objective assessment. The Ki-67 index could provide reliable information and compliment the other prognostic parameters.