john Posted December 10, 2003 Share Posted December 10, 2003 I would make sure the colon cancer is the secondary and not the primary. Ask your doctor how they arrived at the conclusion that the lung is the primary? Identification of Adenocarcinomas Metastatic to the Lung. A key issue in lung tumor diagnosis is the discrimination of a primary lung adenocarcinoma from a distant metastasis to the lung. We identified one distinct hierarchical cluster of 12 samples that most likely represent metastatic adenocarcinomas from the colon. These tumors express high levels of galectin-4, CEACAM1 and liver-intestinal cadherin 17, as well as c-myc, which is commonly over-expressed in colon carcinoma (Fig. 1, CM, and Fig. 3A). Of the 10 samples in this group for which clinical history and/or histopathologic information was available, only 7 samples had been previously diagnosed as metastases of colonic origin (Supplementary file, Sample_Data.xls). Other adenocarcinomas that showed non-lung signatures included AD163, which expressed several breast-associated markers including estrogen receptor and mammaglobin, and was associated with a clinical history and histopathology consistent with breast metastasis (Supplementary data, Figure1_tree.cdt). Also, AD368, which was not identified as a metastasis, expressed high levels of albumin, transferrin, and other markers associated with the liver. Thus, clustering identified suspected metastases of extra-pulmonary origin, including some that were previously undetected, suggesting a pivotal role for gene expression analysis in lung tumor diagnosis. Hum Pathol. 2002 Sep;33(9):915-20. Related Articles, Links /utils/fref.fcgi?http://linkinghub.elsevier.com/retrieve/pii/S0046817702001223> /utils/fref.fcgi?http://linkinghub.elsevier.com/retrieve/pii/S0046817702001223> Expression of cytokeratin 20 in mucinous bronchioloalveolar carcinoma. Shah RN, Badve S, Papreddy K, Schindler S, Laskin WB, Yeldandi AV. Department of Pathology, Northwestern University, Chicago, IL 60611, USA. Mucinous bronchioloalveolar carcinomas (BACs) can closely mimic metastatic adenocarcinoma to the lung both clinically and morphologically. Several studies have demonstrated that the differential expression of cytokeratin 7 (CK7) and cytokeratin 20 (CK20) is a valuable diagnostic tool in differentiating primary pulmonary adenocarcinomas (PPAs) (usually CK7 positive/CK20 negative) from metastatic colonic adenocarcinoma (usually CK7 negative/CK20 positive). The present study is designed to correlate the histologic subtypes of PPA with expression of 7 and 20. A total of 113 cases of bonafide PPA were selected and classified according to the 1999 World Health Organization criteria as adenocarcinoma, NOS (n = 80), nonmucinous BAC (n = 14), and mucinous BAC (n = 19). Representive sections of all the tumors were immunohistochemically analyzed for CK7 and CK20 expression. To evaluate the diagnostic utility of CK7 and CK20 expression, 6 cases of colonic adenocarcinoma metastatic to the lung were tested with the same antibodies and compared with mucinous BAC. Results were expressed in a semiquantitative fashion based on the percentage of positive tumor cells: <10%, focal; 10% to 25%, 1+; 26% to 75%, 2+; > or =76%, 3+. All 113 PPAs exhibited strong, diffuse CK7 expression. With respect to CK20 expression, 17 of the 19 cases (89.4%) of mucinous BAC showed moderate to strong expression of this protein, whereas only 10 cases of conventional adenocarcinomas and 4 cases of nonmucinous BAC exhibited expression. All 6 examples of metastatic colonic adenocarcinomas were negative for CK7 and strongly positive for CK20. In summary, mucinous BAC is distinct from other PPAs by virtue of its CK20 expression. Although the CK7/CK20 immunoprofile is a valuable diagnostic marker for differentiating primary lung adenocarcinoma from metastatic colonic adenocarcinoma, caution should be exercised when dealing with mucinous BAC. Copyright 2002, Elsevier Science (USA). All rights reserved. Quote Link to comment Share on other sites More sharing options...
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