[977] Urothelial Carcinoma with Lymphoepithelioma like Carcinoma Features: A Clinicopathologic Study of Ten Patients.

Angela Wu, James Montie, David Smith, L Priya Kunju. University of Michigan Medical Center, Ann Arbor

Background: Lymphoepithelioma like carcinoma (LEC) is an extremely rare type of mixed/divergent differentiation in urothelial carcinoma and there is limited literature regarding the biologic behavior of this entity.
Design: The clinical, morphologic, and immunohistochemical features of patients in our database from 2000 to 2010 diagnosed with urothelial carcinoma with lymphoepithelioma like carcinoma features were analyzed.
Results: Ten patients were diagnosed with urothelial carcinoma with LEC features. All were older adults (55-84, median age 74) with no gender predilection (M:F=1). Carcinomas were located in the urinary bladder (8), renal pelvis (1), and bladder and ureter (1). All cases had extensive LEC features (>=50%), with three showing exclusive LEC. All had high grade cells arranged in syncytia embedded within a dense lymphoid background. Two patients had a concomitant low grade B cell lymphoma involving adjacent soft tissue/lymph nodes. Immunohistochemistry did not have a significant role in establishing the diagnosis. Most (80%) presented at a high clinical stage (>=cT3). Treatment included radical cystectomy (7), ureterectomy (1), nephroureterectomy (1), neoadjuvant chemotherapy (4) and/or adjuvant chemotherapy (3). Of 5 patients who underwent resection without neoadjuvant chemotherapy, the pathologic stages were pT3 (3), pT2b(1), and pT0(1). Of 4 patients who received neoadjuvant chemotherapy, three had significant downstaging of their tumor at resection (pT1 or pT0) while one had pT3. Follow-up was available for 9 patients; the median duration was 2.6 years (range 0.7-9.5 years ). Seven patients have no evidence of disease; two patients developed distant metastases despite neoadjuvant chemotherapy.
Conclusions: LEC differentiation is usually extensive when present and most often presents at a high clinical stage. In our experience, this subtype of carcinoma has a somewhat mixed response to chemotherapy, but it does not always confer resistance to chemotherapy. Interestingly, two of ten patients had a concomitant low grade B cell lymphoma, which may imply an increased risk of low grade lymphoma associated with this subtype.
Category: Genitourinary (including renal tumors)

Tuesday, March 1, 2011 9:30 AM

Poster Session III # 191, Tuesday Morning


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