Benign adenomatous multicystic kidney tumor (Perlmann's tumor) and renal cortical carcinoma with adenomatous multicystic features: 12 cases.
OBJECTIVES: To re-examine clear cell cystic lesions of the kidney and to assess their potential clinicopathologic significance, as the long-forgotten diagnosis of benign adenomatous multicystic kidney tumor (Perlmann's tumor) has not been cited in the literature in more than 35 years. METHODS: We identified 12 patients between 1959 and 1996 who underwent a radical nephrectomy at our institution and were diagnosed with either adenomatous multicystic clear cell kidney tumor (n = 4) or with renal cell carcinoma (RCC) associated with features of adenomatous clear cell multicystic kidney tumors (n = 8). All diagnoses were reviewed histologically by a single pathologist. RESULTS: Nine of 1 2 patients had Stage T2NOMO disease, and 3 patients had Stage T1 NOMO disease. There were 8 men and 4 women. The average age at the time of surgery was 60.5 years (range 25 to 74). Six patients are still alive with a mean follow-up of 4.7 years (range 1.5 to 16.3) and have no evidence of recurrent disease. Of the 6 patients who died, mean survival time was 8.8 years (range 0 to 15.7). One patient died in the perioperative period, and the other 5 patients died of other causes, unrelated to their kidney tumor. CONCLUSIONS: Adenomatous clear cell multicystic kidney disease may represent a histologically distinct benign neoplasm, and its presence in association with RCC may confer a more favorable prognosis. Its distinction from usual solid hemorrhagic or focally necrotic RCC is important.