[Clinicopathologic analysis of papillary renal cell carcinoma]

To analyze the clinicopathologic and immunohistochemical features and prognosis of papillary renal cell carcinoma (PRCC) in 19 cases.

A retrospective study was performed including reviewing the clinical documents and pathological sections of 19 cases of PRCC. Immunohistochemical staining were performed and follow-up was made in 16 cases.

There were 11 men and 8 women included in this study. The mean age was 52 years (range, 33 to 82 years old). Clinically, most tumors were found incidentally by physical examination because the majority of patients were asymptomatic. Histologically, the PRCC were characterized by varying proportions of papillary and tubular architecture covered by single- or multiple-layer of tumor cells with scanty or voluminous basophilic or eosinophilic cytoplasm. Foam cells and psammoma bodies were seen in some papillary cores and stroma, and the cytoplasm of some tumor cells contained hemosiderin. Of these 19 patients, 12 (63.2%) and 7 (36.8%) were diagnosed as type I and type II PRCC, respectively. The Fuhrman nuclear grade in all the type I PRCC was grade 1 - 2, significantly lower than that in the type II PRCC. Immunohistochemically, the PRCC often showed positive immunostaining for vimentin, EMA, CKpan, CK7, CD10 and p504s. Among the 19 patients, 16 were followed-up from 2 to 67 months. The distant metastasis, including lung, liver and bone metastases were detected in 3 patients at 3, 8, and 9 months after surgery, which were all of type II PRCC. Two patients died of other diseases. The other 11 patients were alive without recurrence or metastasis.

Two subtypes of PRCC show different features of morphology, immunohistochemistry and prognosis. The type II PRCC tends to have unfavorable prognosis in comparison with type I PRCC. The presence of higher nuclear grade, sarcomatoid elements or clear cell carcinoma structure may indicate an aggressive behavior and poor prognosis.