CDX-2 expression in pulmonary fine-needle aspiration specimens: a useful adjunct for the diagnosis of metastatic colorectal adenocarcinoma.
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.
Department of Pathology, Division of Cytopathology, New York University School of Medicine, New York, New York, USA. Pascale.Levine@med.nyu.edu
Pascale Hummel
PH
Levine
Alla
A
Joutovsky
Joan
J
Cangiarella
Herman
H
Yee
Aylin
A
Simsir
D000230:Adenocarcinoma / Q000737:chemistry / Q000175:diagnosis* / Q000473:pathology / Q000556:secondary*; D044963:Biopsy, Fine-Needle / Q000379:methods; D000071616:CDX2 Transcription Factor; D015179:Colorectal Neoplasms / Q000737:chemistry* / Q000175:diagnosis* / Q000473:pathology; D004273:DNA, Neoplasm / Q000032:analysis; D003937:Diagnosis, Differential; D015972:Gene Expression Regulation, Neoplastic; D005801:Genes, Homeobox; D018398:Homeodomain Proteins / Q000032:analysis* / Q000235:genetics; D006801:Humans; D007150:Immunohistochemistry; D008175:Lung Neoplasms / Q000737:chemistry / Q000175:diagnosis* / Q000473:pathology / Q000556:secondary*; D011237:Predictive Value of Tests; D015203:Reproducibility of Results; D015534:Trans-Activators / Q000032:analysis* / Q000235:genetics
D000071616:CDX2 Transcription Factor; D004273:DNA, Neoplasm; D018398:Homeodomain Proteins; D015534:Trans-Activators