title: Pseudocarcinomatous hyperplasia in anaplastic large cell lymphoma, a mimicker of poorly differentiated squamous cell carcinoma: report of a case and review of the literature.
abstract: Pseudocarcinomatous hyperplasia can occasionally be observed in biopsies of CD30-positive lymphoproliferative disorders. It is important to be cognizant of this association, because epithelial hyperproliferation can overshadow large atypical lymphoid cells, leading to an erroneous diagnosis of squamous cell carcinoma (SCC) or keratoacanthoma. Herein, we present a case of anaplastic large cell lymphoma (ALCL) with pseudocarcinomatous hyperplasia simulating a poorly differentiated carcinoma and review the literature on this subject. Immunohistochemical staining with p63 helped delineate the infiltrating tongues of pseudocarcinomatous hyperplasia from the malignant infiltrate. We present this case to raise awareness of the potential for pseudocarcinomatous hyperplasia to occur in the setting of CD30+ lymphoproliferative disorders. Clinicians and dermatopathologists should consider the possibility of ALCL or lymphomatoid papulosis when examining lesions with features of inflamed SCC, especially if the tumor presents on a site or in a patient that is not typical of SCC.
authors.affiliation: New York University School of Medicine, New York, NY, USA.
authors.forename: Alexandra
authors.initials: A
authors.lastname: Price
authors.affiliation: Rutgers/Robert Wood Johnson School of Medicine, Department of Dermatology, New York, NY, USA.
authors.forename: Jason H
authors.initials: JH
authors.lastname: Miller
authors.affiliation: Ackerman Academy of Dermatopathology, New York, NY, USA.
authors.forename: Jacqueline M
authors.initials: JM
authors.lastname: Junkins-Hopkins
mesh_terms: D000369:Aged, 80 and over; D002294:Carcinoma, Squamous Cell / Q000378:metabolism / Q000473:pathology*; D003937:Diagnosis, Differential; D006801:Humans; D006965:Hyperplasia; D007636:Keratoacanthoma / Q000378:metabolism / Q000473:pathology; D017730:Ki-1 Antigen / Q000378:metabolism; D017728:Lymphoma, Large-Cell, Anaplastic / Q000378:metabolism / Q000473:pathology*; D017731:Lymphomatoid Papulosis / Q000378:metabolism / Q000473:pathology; D008297:Male; D008565:Membrane Proteins / Q000378:metabolism; D012878:Skin Neoplasms / Q000378:metabolism / Q000473:pathology*
chemical_list: C081876:CKAP4 protein, human; D017730:Ki-1 Antigen; D008565:Membrane Proteins
keywords: CD30 lymphoproliferative disorders; anaplastic large cell lymphoma; epidermal hyperplasia; lymphoma; pseudocarcinomatous hyperplasia; pseudoepitheliomatous hyperplasia