[710] Renal Carcinomas Arising in Patients with Autosomal Dominant Polycystic Kidney Disease (ADPKD): A Clinicopathological Review

S Bai, O Hameed. University of Alabama School of Medicine, Birmingham, AL

Background: Previous studies have suggested that renal neoplasms arising in patients with ADPKD are more often bilateral and multicentric than those arising in the general population. This study was performed to determine the prevalence of the different types of renal cell carcinoma (RCC) and potential precursor lesions developing in this patient population.
Design: Kidneys excised for ADPKD over a 14 year period were reviewed to identify those with associated carcinoma. Clinical and follow up information was obtained from clinical charts and the hospital cancer registry. All tumors were histologically reviewed and characterized pathologically, aided by ancillary methods (e.g. immunohistochemistry) when necessary.
Results: Ninety five kidneys were excised from 50 patients including 32 (64%) males and 18 (36%) females (5:3 ratio). There were 39 (78%) Caucasian (C) and 11 (22%) African-American (AA) patients (4:1 ratio). Thirteen patients (26%) developed RCCs including 6 (46%) C and 7 (54%) AA patients (<1:1 ratio). The proportion of C and AA patients with RCC were 6/39 (15%) and (7/11) (64%), respectively (P = 0.003). The age of the patients ranged from 32 to 62 years (mean, 46 yrs). A total of 24 RCCs were identified in 15 kidneys (2 patients had bilateral tumors) with multifocal disease seen in 5 kidneys (33%). The size of the tumors ranged from 0.5-10 cm (mean, 2.3 cm). Sixteen (67%) tumors were classified as papillary RCC (type I, 9; type II, 6; mixed, 1), 4 (17%) as clear cell papillary RCC, 2 (8%) as clear cell RCC, 1 (4%) as collecting duct carcinoma with rhabdoid features, and 1 (4%) as unclassified RCC. Fifteen (63%) of the tumors had a Fuhrman grade of II with the remaining 9 (37%) being grade III. Except for one case, all tumors were confined to the kidney and without venous invasion. After a median follow up of 48 mo (range, 2-169 mo), 8 (62%) patients were alive, 4 expired (including two who died with disease after 2 and 4 months, respectively) and 1 patient was lost to follow up. One of the deceased and 7 of the living patients were cancer-free at last follow up; the status of disease was unknown in the remaining 2 patients.
Conclusions: Patients with ADPKD, especially AA patients, are at an increased risk for development of RCC which is not infrequently bilateral and/or multifocal. Most tumors are represented by papillary and clear cell-papillary RCC, are of low stage, and associated with a good outcome. Evaluation of potential precursor lesions in these cases and in ADPKD patients without carcinoma is ongoing.
Category: Genitourinary (including renal tumors)

Monday, March 9, 2009 9:30 AM

Poster Session I Stowell-Orbison/Autopsy Award # 111, Monday Morning