[374] The Utility of TTF-1 & Napsin A Dual Immunostain in the Distinction of Metastatic Lung Adenocarcinoma from Other Metastatic Adenocarcinoma in Body Fluid Specimens.

Lili Geng, Tamar Giorgadze, Pamela Archuletta, Sudeshna Bandyophadhyay, Jining Feng, Shashi Madan, Dongping Shi, Seema Sethi, Paul Tranchida, Vinod B Shidham. Wayne State University, Detroit, MI

Background: Discrimination of metastatic adenocarcinoma of pulmary origin from metastatic adenocarcinoma of other primary sites is challenging. TTF-1 has been used as the predominant immunomarker to confirm lung origin. Napsin A is a recently charaterized marker which has shown high specificity for lung tissue in surgical pathology specimens. In this study we evaluated whether novel dual TTF-1 & Napsin A immunostain increases the sensitivity and specificity in diagnosing metastatic lung adenocarcinoma in body fluids.
Design: Paraffin embedded adequately cellular body fluid cell blocks from 19 consecutive patients with a diagnosis of metastatic adenocarcinoma were retrieved (12 metastatic lung adenocarcinoma, 2 colon, 5 breast). Adequately cellular levels were immunostained using novel TTF-1 & Napsin A multiplex cocktail. The presence of one or more individual cells with convincing brown nuclear TTF-1, red cytoplasmic Napsin A staining, or cells with TTF-1/Napsin A co-expression were interpreted as "positive".
Results: Of the 12 metastatic lung adenocarcinoma, 11 were positive for both TTF-1 & Napsin A; 1 case was negative for TTF-1 but was positive for Naspin A, and 1 case was negative for Napsin A but was positive for TTF-1. The 2 colon and 5 breast cases were all negative for both TTF-1 and Napsin A (specificity 100% and sensitivity 100%).
Conclusions: The dual immunostain TTF-1 & Napsin A is highly specific and sensitive for lung adenocarcinoma, and can be highly useful in differentiating metastatic lung adenocarcinoma from metastasis from othe body sites including breast and colon.
Category: Cytopathology

Monday, February 28, 2011 9:30 AM

Poster Session I Stowell-Orbison/Surgical Pathology/Autopsy Awards Poster Session # 65, Monday Morning


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