[1076] Clear Cell Papillary Renal Cell Carcinoma-Like Tumors in Patients with Von Hippel-Lindau Disease Are Unrelated to Sporadic Clear Cell Papillary Renal Cell Carcinoma

Sean R Williamson, Shaobo Zhang, John N Eble, David J Grignon, Guido Martignoni, Matteo Brunelli, Stefano Gobbo, Lee Ann Baldridge, Liang Cheng. Indiana University, Indianapolis, IN; University of Verona, Verona, Italy

Background: Clear cell papillary renal cell carcinoma (CCPRCC) shares morphologic overlap with clear cell renal cell carcinoma, though it lacks the typical chromosome 3p and VHL gene abnormalities. Rare cases have been reported in von-Hippel Lindau (VHL) patients (germline mutation of the VHL gene), the significance of which is uncertain.
Design: Renal tumor slides from patients with VHL disease were examined for morphologic features of CCPRCC. CCPRCC-like tumors were studied with immunohistochemistry for CK7, carbonic anhydrase IX (CAIX), CD10, and alpha-methylacyl-coA-racemase (AMACR). Fluorescence in situ hybridization (FISH) was performed (5 tumors) with probes to chromosomes 3p14, 3p25, 7 and 17. Clear cell renal cell carcinomas from the same patients (n=2) and VHL patients without CCPRCC-like tumors (n=8) were also studied for comparison.
Results: Fourteen tumors with CCPRCC-like features were identified in 4 VHL patients. Gross appearance in 2 tumors closely resembled clear cell renal cell carcinoma (yellow-orange), while other tumors were tan, red-brown, or extensively cystic. Histologic features included: prominent papillary structures (64%), small papillary tufts (79%), flattened peripheral cysts (64%), branched tubules (71%), and “secretory cells” with apically-aligned nuclei (43%). The typical immunoprofile of CCPRCC (CK7+, CAIX+, CD10-, AMACR-) was observed in only 2/11 stained tumors (18%), both from the same patient, one of which showed 3p deletion by FISH. The remainder showed negative or focal CK7 reactivity (55%), diffuse, strong expression of CD10 (64%), or both (18%). Three tumors (27%) also showed strong AMACR staining. Several possessed 3p deletion by FISH (60%), similar to those of VHL patients without CCPRCC-like tumors (75%).
Conclusions: Tumors that histologically closely resemble CCPRCC occur in patients with VHL disease, but they usually lack the typical immunohistochemical and molecular profile of sporadic CCPRCC, suggesting that they do not share the same carcinogenesis.
Category: Genitourinary (including renal tumors)

Monday, March 4, 2013 9:30 AM

Poster Session I Stowell-Orbison/Surgical Pathology/Autopsy Awards Poster Session # 166, Monday Morning

 

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