title: Leukemoid reaction: a diagnostic clue in metastatic carcinoma mimicking classic Hodgkin lymphoma.
abstract: We report on 2 patients who were initially suspected to have classic Hodgkin lymphoma because of lymphadenopathy and the presence of Reed-Sternberg-like cells. Both patients had an associated leukemoid reaction (using a threshold leukocyte count of 50 000/microL) and were eventually diagnosed with metastatic carcinoma. Disseminated carcinoma can mimic Hodgkin lymphoma clinically, radiologically, and histologically. Reed-Sternberg-like cells may be found in carcinomas, and they represent a particularly challenging diagnostic pitfall for the unwary. When these cells lead to a suspicion of Hodgkin lymphoma, the presence of a leukemoid reaction should prompt the pathologist to question the diagnosis. Misdiagnosis can be avoided by the use of cytokeratin whenever a leukemoid reaction is present in a suspected case of Hodgkin lymphoma.
authors.affiliation: Department of Pathology, State University of New York Upstate Medical University, Syracuse 13210, USA. mukhopas@upstate.edu
authors.forename: Sanjay
authors.initials: S
authors.lastname: Mukhopadhyay
authors.forename: Surabhi
authors.initials: S
authors.lastname: Mukhopadhyay
authors.forename: Katalin
authors.initials: K
authors.lastname: Banki
authors.forename: Shirish
authors.initials: S
authors.lastname: Mahajan
mesh_terms: D000310:Adrenal Gland Neoplasms / Q000556:secondary*; D000328:Adult; D000368:Aged; D002277:Carcinoma / Q000175:diagnosis* / Q000556:secondary*; D003937:Diagnosis, Differential; D017809:Fatal Outcome; D006689:Hodgkin Disease / Q000175:diagnosis*; D006801:Humans; D007680:Kidney Neoplasms / Q000473:pathology; D007955:Leukemoid Reaction / Q000175:diagnosis*; D008175:Lung Neoplasms / Q000473:pathology; D008297:Male; D012186:Retroperitoneal Neoplasms / Q000556:secondary*