A Pathological Study of Renal Cell Carcinoma

Park, Kwang Hwa; Shin, Dong Hwan; Choi, In Joon

Abstract

The most common malignant renal neoplasm is renal cell carcinoma. It is estimated that renal cell carcinoma accounts for 1% of all primary malignancies in Korea. Rell cell carcinoma presents diverse clinical courses with gross, histopathologic features. It has been known to be very difficult tumor to predict its clinical prognosis. In Korea, many studies have been reported concerning the clinical aspects of renal cell carcinoma. However, pathological studies of renal cell carcinoma are very few even though studies of nuclear grade have been attempted recently. We reviewed 93 cases of renal cell carcinoma examined in the period from 1978 to 1987 in the department of pathology, Yonsei university college of medicine, Yongdong Severance hospital, Wonju college of medicine and analyzed the histopathologic classification, including nuclear grade according to the Fuhrman's method. We abtained the following results by studying the relationship of the factors which had been known as correlated with the prognosis. 1) The ages of patients ranged from 9 to 74 years with a peak in the 6th decade. 2) The most common symptoms of the patients were hematuria, mass and pain, in that oder, and 7 patients complained to specific symptoms. The incidentally found cases characterized stage I, nuclear grade 2 small tumor size (not more than 4 cm) and clear cell type. 3) The renal cell carcinoma was more frequently located in the left kidney than the right by a ratio of 1.25 : 1. The incidence of intrarenal location was divided to the upper pole, 40% : mid portion, 29% : lower pole, 23% : diffuse involvement, 8%. The tumor shoing diffuse growth pattern had a large size, high nuclear grade and mixed cells. 4) The tumor size averaged 8 cm and there was no significant relationship between the size and stage. Seven cases of neoplasms not more than 3 cm were seen, of which 2 cases revealed an outcome of distant metastasis. 5) The histological pattern showed major solid, 53% : tubular, 11% : mixed, 18% : papillary, 9% and sarcomatoid type 9%. The sarcomatoid type was characterized by grade 4, a larger size(more than 10 cm), advanced stage. 6) There was no special relationship between the stage and grade but mostly grade 2 occupied the stage I. 7) The clear cell type was predominantly noted at grade 2 (65%), at the stage I (63%), granular or mixed cell type at grade 3 (87%), 4 (70%). According to these results, the tumors showing a sarcomatoid histologic pattern, diffuse growth pattern had unfavorable prognostic factors, and are thus estimated to have a poor prognosis. But the case which were incidentally found have favorable prognostic factors and probably a better prognosis. The tumor size alone can not exactly predict the metastasis and is not correlated with the stage. Small renal cell neoplasm (not more than 3 cm) generally has unfavorable prognostic factors and should be considered potentially malignant. The high grade frequently has granular cytoplasm. This represents the relationship between grade and cytoplasm, poor prognosis in the granular cell than the clear. The renal cell carcinoma shows variable prognosis and thus the prognosis should be estimated by all the factors. Nuclear grade can be used as one of the useful prognostic factors.