Onkológia 4/2012

Sarcomatoid differentiation as a histopathological prognostic parameter in renal cell carcinoma

Renal cell carcinoma (RCC) is currently one of the most frequent urological malignancies. One of the important histological findings, which reflect biological behaviour of RCC and also provide significant prognostic data are sarcomatoid changes of tumor. In our paper we evaluated the incidence of sarcomatoid changes in renal cell carcinomas and their relationship with other clinico-pathological parameters. A study group consisted of 159 cancers from 157 patients (95 men, 62 women) in the age rage from 18 to 82 years. Out of all cases we found 18 carcinomas (11.3%) having varying degrees of sarcomatoid changes. These tumors were obtained from 18 subjects (11 men, 7 women) between 45 and 82 years of age (mean age 69.1 years). Among them, there were 13 conventional clear cell RCCs, 1 papillary RCC, 2 unclassified RCCs and 2 carcinomas, that entirely consisted of sarcomatoid tissue, were classified as sarcomatoid RCCs. Histologically, sarcomatoid component predominantly composed of spindle cells population with varying degrees of anaplasia and sometimes exhibited rhabdoid features. Six cases corresponded to the pathological stage limited to the kidney (pT1 and pT2) and ten cases were diagnosed in pathological stage with extrarenal propagation (pT3 and pT4). Four patients had metastases in the regional lymph nodes. Almost all cancers showed necrosis. Since sarcomatoid changes in RCC are usually associated with negative prognostic parameters and much less favourable prognosis of disease, if present, pathologist must describe them in a biopsy report. From a clinical point of view, these patients require more careful follow-up, as the literature data indicate the majority of them have metastases at the time of diagnosis.

Keywords: renal cell carcinoma, sarcomatoid changes, prognosis.