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PD ‐1, S‐100 and CD1a expression in pseudolymphomatous folliculitis, primary cutaneous marginal zone B‐cell lymphoma ( MALT lymphoma) and cutaneous lymphoid hyperplasia
Author(s) -
Goyal Amrita,
Moore Johanna B.,
Gimbel Devon,
Carter Joi B.,
Kroshinsky Daniela,
Ferry Judith A.,
Harris Nancy L.,
Duncan Lyn M.
Publication year - 2015
Publication title -
journal of cutaneous pathology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.597
H-Index - 75
eISSN - 1600-0560
pISSN - 0303-6987
DOI - 10.1111/cup.12440
Subject(s) - pseudolymphoma , malt lymphoma , pathology , lymphoma , folliculitis , medicine , lymphoid hyperplasia , cutaneous lymphoma , immunohistochemistry , mycosis fungoides
Background Pseudolymphomatous folliculitis is a lymphoid proliferation that clinically and histopathologically mimics primary cutaneous extranodal marginal zone lymphoma of mucosa‐associated lymphoid tissue ( MALT lymphoma). In this study, we assessed the diagnostic value of three immunohistochemical markers, programmed death‐1 ( PD ‐1), CD1a and S100 . Methods We evaluated 25 cases of cutaneous lymphoid proliferations with established diagnoses, including 9 patients with pseudolymphomatous folliculitis, 11 with MALT lymphoma, and 5 with cutaneous lymphoid hyperplasia ( CLH ). The clinical, histopathologic and immunohistochemical characteristics were reviewed and three major characteristics assessed: (a) proportion of T cells expressing PD ‐1, (b) pattern of expression of CD1a by dendritic cells and (c) pattern of expression of S100 by dendritic cells. Results We found pseudolymphomatous folliculitis to have a significant increase in PD ‐1+ T cells compared with MALT lymphoma (p < 0.0001). The pattern of CD1a staining is also informative: MALT lymphoma is significantly more likely to demonstrate a peripheral concentration of CD1a + dendritic cells around lymphoid nodules than pseudolymphomatous folliculitis (p < 0.0003) or CLH (p < 0.05). Pseudolymphomatous folliculitis demonstrates an interstitial distribution of CD1a + cells more often than MALT lymphoma (p < 0.04). S100 staining was not a helpful discriminator. Conclusions Histopathologic factors including PD ‐1 and CD1a staining patterns may allow for more certainty in distinguishing lymphoid hyperplasia, including pseudolymphomatous folliculitis, from MALT lymphoma.