[803] Carcinomas with Similar Morphology and Immunohistochemical Profile: Does GATA3 Make a Difference?

Tatjana Antic, Lei Zhao, Aliya Husain, Katja Gwin, M Kamran Mirza, Mark Lingen, Maria Tretiakova. University of Chicago, Chicago, IL

Background: Conventional urothelial carcinoma (UC) with or without squamous differentiation has been known to share overlapping morphology and immunohistochemical profile with other carcinomas, specifically squamous cell carcinoma (SCC) of the lung, cervix and head and neck. All of those express immunohistochemical stains CK7 and p63 in variable quantities. GATA3 is a recently described marker of urothelial differentiation, therefore potentially useful in detecting metastatic tumors of urothelial origin. To analyze the specificity of GATA3 in distinguishing metastatic UC from its morphologic and immunophenotypic mimics, we investigated the expression of GATA3 in SCC of cervix, head and neck and non-small carcinomas of the lung including SCC (primary and metastatic).
Design: GATA3 immunostaining was performed on tissue microarray slides consisting of 478 cases. Those included 213 cases of primary and metastatic UC, 74 SCC cases of head and neck, 51 cervical SCC, 81 cases of lung non-small cell carcinoma including 25 SCC cases and 23 cases of metastatic non-small cell lung carcinoma in lymph nodes and brain. Ductal (N=31) and lobular (N=5) breast cancers were added as a known positive control.
Results: The primary and metastatic UC consistently express GATA3 in 80.8% of cases. Non-small cell lung carcinoma (both primary and metastasis) shows no expression except in one case, in which GATA3 is positive in both primary and metastatic tumor. 8.1% of head and neck SCC demonstrated positive staining for GATA3 and 15.7% of cervical SCC was positive for GATA3.

GATA3 expression in urothelial carcinoma and its morphologic and immunophenotypic mimickers
Tumor originGATA3 positive % (positive/total cases)
Bladder80.8% (172/213)
Cervix15.7% (8/51)
Lung (primary)1.2% (1/81)
Lung (metastatic)4.3% (1/23)
Head and neck8.1 % (6/74)
Breast80.6% (29/36)

Conclusions: GATA3 is a sensitive marker for both urothelial and breast carcinoma; nevertheless, the morphology and expression of p63 in UC should be helpful in differentiating it from breast carcinoma. GATA3 also demonstrates high specificity in distinguishing UC from its morphological and immunophenotypic mimics, such as head and neck carcinoma and lung cancer. However, cervical SCC demonstrated a relatively higher percentage of positive staining, which may pose a potential pitfall in female patients.
Category: Genitourinary (including renal tumors)

Monday, March 4, 2013 1:00 PM

Poster Session II # 185, Monday Afternoon


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