Abdominal seeding of renal cell carcinoma: radiologic, pathologic, and prognostic features

We analyzed radiologic and histologic characteristics, and prognosis of abdominal seeding from renal cell carcinoma (RCC).

Consecutive 25 patients with RCC and histologically or radiologically diagnosed abdominal seeding were analyzed. No patient had another type of malignancy. Histologic subtype, Fuhrman grade, sarcomatoid differentiation, and T-stage of primary tumors were assessed. Pre- or postoperative presentation of seeding was investigated. Median survival time and RCC-specific survival rates were evaluated.

Of 25 patients, 15 (60%) died and 4 (16%) were hopelessly discharged (median follow-up time, 6 months; range 1-62 months). Histologic subtypes were clear cell (76%, 19/25), papillary (16%, 4/25), chromophobe (4%, 1/25), and poorly differentiated (4%, 1/25). Fuhrman grades were 4 (48%, 12/25), 3 (36%, 9/25), 2 (12%, 3/25), and unknown (4%, 1/25). T-stage of the four patients with grade 2 or unknown was 3a. Sarcomatoid differentiation and postoperative occurrence were found in 32% (8/25) and 80% (20/25), respectively. Median survival time was 13 months, and 1-year, 2-year, and 3-year RCC-specific survival rates were 51%, 41%, and 31%, respectively.

Abdominal seeding may occur in various subtypes of RCC with high Fuhrman grade including sarcomatoid differentiation or high T-stage, and appears to be related to poor prognosis.