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CDX‐2 expression in pulmonary fine‐needle aspiration specimens: A useful adjunct for the diagnosis of metastatic colorectal adenocarcinoma
Author(s) -
Levine Pascale Hummel,
Joutovsky Alla,
Cangiarella Joan,
Yee Herman,
Simsir Aylin
Publication year - 2006
Publication title -
diagnostic cytopathology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.417
H-Index - 65
eISSN - 1097-0339
pISSN - 8755-1039
DOI - 10.1002/dc.20403
Subject(s) - medicine , adjunct , metastatic adenocarcinoma , adenocarcinoma , lung , oncology , fine needle aspiration , pathology , cancer , biopsy , philosophy , linguistics
CDX‐2 is a homeobox gene, which encodes a transcription factor that plays a vital role in the development and differentiation of intestinal epithelial cells. Recent studies showed that CDX‐2 protein expression by immunohistochemistry (IHC) has a high predictive value for confirming the diagnosis of colorectal adenocarcinoma (ACA). The differentiation of primary pulmonary ACA from metastatic colorectal ACA can be extremely challenging on fine‐needle aspiration (FNA). The results of immunostains for TTF‐1, CK 7, and CK 20 may be controversial in the differential diagnosis. In this study, we evaluated the clinical utility of CDX‐2 in lung FNA specimens. Cell blocks from 41 primary lung and 20 colorectal ACAs metastatic to the lungs were retrieved. Cell block sections were immunostained with a CDX‐2 monoclonal antibody. Sensitivity and specificity of CDX‐2 for colorectal ACA was 75 and 100%, respectively. All five cases negative for CDX‐2 were moderately to poorly differentiated colorectal ACAs. Our study confirms that CDX‐2 is a highly useful immunohistochemical marker for the differentiation of primary pulmonary ACA from colorectal ACA metastatic to the lungs in FNA specimens. Of diagnostic importance is the loss of CDX‐2 immunoreactivity in poorly differentiated colorectal ACAs. Diagn. Cytopathol. 2006;34:191–195. © 2006 Wiley‐Liss, Inc.