Napsin A is a useful marker for metastatic adenocarcinomas of pulmonary origin

• DOI: 10.1111/his.12383
• Publication Date: 2014-01-31T11:14:14Z
• Authors: Moon‐Young Kim; Heounjeong Go; Jaemoon Koh; Kyoungbun Lee; Hye‐Sook Min; Min‐A Kim; Yoon Kyung Jeon; Hye‐Seung Lee; Kyung‐Chul Moon; So Yeon Park; Woo‐Ho Kim; Doo Hyun Chung
• Keywords: DNA-Binding Proteins; 0301 basic medicine; 03 medical and health sciences; Lung Neoplasms; Tissue Array Analysis; Biomarkers, Tumor; Aspartic Acid Endopeptidases; Humans; Adenocarcinoma; Neoplasm Metastasis; Immunohistochemistry; Transcription Factors

AimsTo address whether napsin A is useful for identifying metastatic adenocarcinomas of pulmonary origin.Methods and resultsFifty‐four cases of adenocarcinoma that metastasized from the lungs to various sites and 1762 cases of carcinoma from various organs were immunostained for napsin A, TTF‐1, CK7, CK20 and CDX2 using tissue microarray. The expression patterns of napsin A and TTF‐1 in metastatic pulmonary adenocarcinomas were compared with matched primary lung tumours. Napsin A and TTF‐1 were expressed in 87.0% and 81.5% of the metastatic pulmonary adenocarcinomas, respectively. Although there was no significant difference in the positivity of napsin A and TTF‐1 as a single marker in metastatic pulmonary adenocarcinomas, the expression scores for napsin A were much higher than those for TTF‐1 (P < 0.001). Moreover, the positivity and expression scores of napsin A in primary pulmonary adenocarcinomas were maintained in metastatic adenocarcinomas better than TTF‐1. Most non‐pulmonary adenocarcinomas were negative for napsin A, except for renal cell carcinomas (13.4%), ovarian adenocarcinomas (7.1%) and uterine endometrial adenocarcinomas (14.5%). In particular, clear cell adenocarcinomas of ovary (68.8%) and uterus (66.7%) frequently expressed napsin A.ConclusionsThese data suggest that napsin A may be a useful marker for identifying metastatic adenocarcinomas of pulmonary origin in combination with TTF‐1.