title: Mesothelial hyperplasia with reactive atypia: diagnostic pitfalls and role of immunohistochemical studies-a case report.
abstract: The cytomorphologic features of highly reactive mesothelial cells can be difficult to distinguish from malignant cells. We report on an unusual case of mesothelial hyperplasia in a pericardial effusion. The specimen contained bizarre-shaped cells and large tissue fragments in a patient with a history of lung carcinoma. The atypical cells were negative for CEA and LeuM-1 and positive for cytokeratins (AE1/3) and HBME-1. Strong HBME-1 positivity supported a mesothelial origin of the atypical cells and led to the diagnosis of reactive mesothelium. While HBME-1 cannot be used as the sole marker to establish an mesothelial origin; its use in a immunohistochemistry panel may be useful in individual cases to distinguish reactive mesothelial cells from carcinoma in effusion cytology. Diagn. Cytopathol. 2000;22:113-116.
authors.affiliation: Division of Cytopathology and Cytometry, Department of Pathology and Laboratory Medicine, University of Pennsylvania Medical Center, Philadelphia, PA 19104, USA.
authors.forename: A
authors.initials: A
authors.lastname: Lee
authors.forename: Z W
authors.initials: ZW
authors.lastname: Baloch
authors.forename: G
authors.initials: G
authors.lastname: Yu
authors.forename: P K
authors.initials: PK
authors.lastname: Gupta
mesh_terms: D000230:Adenocarcinoma / Q000175:diagnosis; D014408:Biomarkers, Tumor / Q000378:metabolism; D003581:Cytodiagnosis; D003937:Diagnosis, Differential; D003951:Diagnostic Errors; D004848:Epithelium / Q000378:metabolism / Q000473:pathology; D005260:Female; D006801:Humans; D006965:Hyperplasia / Q000473:pathology; D007124:Immunoenzyme Techniques; D008175:Lung Neoplasms / Q000175:diagnosis* / Q000378:metabolism; D008654:Mesothelioma / Q000175:diagnosis* / Q000378:metabolism; D008875:Middle Aged; D010490:Pericardial Effusion / Q000378:metabolism / Q000473:pathology*; D010493:Pericarditis / Q000175:diagnosis* / Q000378:metabolism
chemical_list: D014408:Biomarkers, Tumor