title: Cytokeratin positivity in anaplastic large cell lymphoma: a potential diagnostic pitfall in misdiagnosis of metastatic carcinoma.
abstract: Cytokeratin (pan) and epithelial membrane antigen (EMA) were considered as commonly useful epithelial markers to distinguish cancer from lymphoma, but the expression of cytokeratin (pan) and EMA had also been seen in some lymphomas. Here, we presented an unusual case of anaplastic large cell lymphoma (ALCL) absence of some lymphoid markers (Including CD3, CD20, Pax-5, CD45Ro) and positive for cytokeratin (pan) and EMA, which was misdiagnosed as metastatic carcinoma. Our case suggested that the epithelial markers (including cytokeratin and EMA) show an overlap with that of ALCL, which represented a diagnostic pitfall for confusing ALCL with metastatic carcinoma.
authors.affiliation: Department of Pathology, First Affiliated Hospital and College of Basic Medical Sciences, China Medical University, Shenyang, PR China.
authors.forename: Qingfu
authors.initials: Q
authors.lastname: Zhang
authors.forename: Jian
authors.initials: J
authors.lastname: Ming
authors.forename: Siyang
authors.initials: S
authors.lastname: Zhang
authors.forename: Bo
authors.initials: B
authors.lastname: Li
authors.forename: Xue
authors.initials: X
authors.lastname: Han
authors.forename: Xueshan
authors.initials: X
authors.lastname: Qiu
mesh_terms: D000328:Adult; D014408:Biomarkers, Tumor / Q000378:metabolism*; D001706:Biopsy; D003951:Diagnostic Errors; D006801:Humans; D047908:Intracellular Signaling Peptides and Proteins; D007633:Keratins / Q000378:metabolism*; D017730:Ki-1 Antigen / Q000378:metabolism; D008198:Lymph Nodes / Q000378:metabolism / Q000473:pathology; D008207:Lymphatic Metastasis / Q000175:diagnosis*; D017728:Lymphoma, Large-Cell, Anaplastic / Q000175:diagnosis* / Q000378:metabolism*; D008297:Male; D018396:Mucin-1 / Q000378:metabolism*; D011506:Proteins / Q000378:metabolism; D009687:Nuclear Proteins
chemical_list: D014408:Biomarkers, Tumor; D047908:Intracellular Signaling Peptides and Proteins; D007633:Keratins; D017730:Ki-1 Antigen; D018396:Mucin-1; D011506:Proteins; C526165:WDR48 protein, human; D009687:Nuclear Proteins
keywords: Anaplastic large cell lymphoma; anaplastic lymphoma kinase; immunohistochemistry