Objective: To study the clinicopathologic characteristics of renal collecting duct carcinoma (CDC).
Methods: A retrospective study was done in 10 cases of CDC.
Results: Among 466 cases of renal cell carcinoma admitted in our Institute between January 1989 and June 30, 1999, 10(2.1%) cases of CDC were identified. Seven presented with gross hematuria and 3 with abdominal pain. Radical nephrectomy was done in 9 patients, enucleation of tumor in one. The primary tumor was located predominantly in the renal medulla. Histologic examination showed prominent tubular or tubulopapillary structures. Sarcomatoid carcinoma, cystadenocarcinoma, nests and cords of tumor cells in desmoplastic stroma were identified in some cases. High molecular weight cytokeratin 34 beta E12 was positive in 8 cases and peanut agglutinin in 7 cases. According to Fuhrman's nuclear grade, one was in G2, 4 were in G3 and 5 in G4. Six patients died of metastases within 3 to 23 months (mean 13.3 months), one died of heart disease with tumor free after 19 months, two survived with tumor free for 14 months and 39 months, respectively, one lost from follow-up.
Conclusion: CDC is a distinctive renal cell carcinoma with prominent clinical appearance and progressive clinical course.