Variants of renal cell carcinoma; an experience at a single centre in Pakistan

Renal cell carcinomas (RCC) have been considered as a single entity, until recently. Today, however, these are not considered as a single tumour but instead represent various distinguishable entities, each having unique histology, cytogenetic and molecular features. The variants of renal cell carcinoma can be easily recognized histologically and hence one can identify tumours having similar clinical course, morphology, genetics, prognosis and possibly treatment. This descriptive study carried over a period of one and a half year at Shifa International Hospital, Islamabad, focuses on presenting our data of various variants of renal cell carcinoma and the need for their recognition as the correct diagnosis may help to modify the therapeutic protocol. During the study period a total of 13 cases of RCC were diagnosed with the clear cell variant as the most frequent type (n=9; 69.2%). There was one case each of chromophobe renal carcinoma, medullary carcinoma, mucinous tubular and spindle cell carcinoma and multilocular cystic renal carcinoma. The average size of tumour ranged from 2.8 cm to 9.0 cm. Furhman's nuclear grade 2 was most frequently encountered (n=6; 46%) while the most frequent pathologic tumour stage was pT2 (n=7; 54%). This series is limited due to small sample size. More such studies on a larger scale with incorporation of follow up data are recommended to obtain population based statistics and identify biologically favourable variants in which nephron sparing surgery may be a suitable option.