[861] GATA3 Is a Useful Marker for Signet Ring Adenocarcinoma of the Urinary Bladder

Carla L Ellis, Alex G Chang, Ashley Cimino-Mathews, Pedram Argani, Ramy Youssef, Payal Kapur, Elizabeth A Montgomery, Jonathan I Epstein. Johns Hopkins Hospital, Baltimore, MD; University of Texas Southwestern Medical Center, Dallas, TX

Background: Primary adenocarcinomas (adenoca.) of the bladder must be differentiated from metastatic adenoca. from other sites, particularly the gastrointestinal tract and breast. To date, while nuclear beta-catenin labeling supports an intestinal adenoca., no immunohistochemical markers have been identified that are specific for adenoca. of the urinary bladder. GATA-3 labels urothelial and breast carcinomas. However, no prior study has evaluated the expression of GATA3 in primary bladder adenoca.
Design: Tissue microarrays (TMAs) were constructed containing 48 primary bladder adenoca. They contained 18 poorly differentiated signet ring adenoca, 30 conventional adenoca. (28 bladder, 2 urachal). Contiguous spread from other organs was excluded by colonoscopy and imaging, surgical examination, and at least 6 months of clinical follow up showing no subsequent presentation of an extra-vesical primary tumor. Additionally, TMAs containing 32 primary gastric signet ring adenoca. and 36 primary lobular breast carcinomas were evaluated. The TMAs contained 3-5 cores per tumor and were labeled with GATA3, estrogen receptor (ER), progesterone receptor (PR), and GCDFP.
Results: Diffuse nuclear GATA3 labeling was seen in 8/18 (44%) primary adenoca. with signet ring features, and 1/28 (3%) conventional bladder adenoca. (p=0.002). 2 urachal adenoca. were negative for GATA3. Of the 11 signet ring adenoca. without extracellular mucin, 7 (63.6%) were GATA3 positive, whereas all 7 signet ring adenoca. with extracellular mucin were negative for GATA3. No nuclear GATA3 labeling was seen in any gastric signet ring carcinomas. Diffuse, moderate-strong nuclear GATA3 labeling was seen in 36/36 (100%) primary lobular breast carcinomas, one of which was ER-negative. All bladder adenoca. were negative for negative for GCDFP, ER and PR.
Conclusions: Nuclear GATA3 labeling is a specific marker for distinguishing primary signet ring adenocarcinomas of the urinary bladder from gastric signet ring carcinomas. However, GATA3 is not that sensitive seen in only 44% of primary signet ring cell bladder adenocarcinoma. GATA3 is not helpful for site of orgin of adenocarcinoma involving the bladder lacking signet ring cells or in adenoca. with signet ring cells and extracellular mucin. Clinical and radiographic features along with immunohistochemistry for ER, PR and GCDFP must be used to exclude metastatic lobular breast carcinoma in female patients.
Category: Genitourinary (including renal tumors)

Tuesday, March 5, 2013 9:30 AM

Poster Session III # 104, Tuesday Morning


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