Abstract

Lymphomatoid papulosis (LYP) is a rare cutaneous lymphoproliferative disorder that is often self-limiting. These lesions are subclassified on the basis of histopathologic features simulating different cutaneous lymphomas. Type D LYP was recently included in the 2018 WHO classification, and comprises less than 5% of all LYP cases. It shares histopathologic features with aggressive epidermotropic cutaneous T-cell lymphoma, but is distinguished from this entity by the presence of CD30. Here, we present a case of type D LYP that occurred in a 48-year-old woman with a five-year history of recurrent pruritic, ulcerative papules of the bilateral upper and lower extremities and the trunk. Histopathologically, there was a moderately dense perivascular and periadnexal dermal infiltrate consisting of atypical lymphocytes. The overlying epidermis showed acanthosis with mild spongiosis, hyperkeratosis and parakeratosis with mild lymphocyte epidermotropism. The dermal lymphocytes were enlarged and markedly atypical, with plasmacytoid and histiocytoid features, nuclear enlargement, prominent nucleoli, and abundant cytoplasm. The intraepidermal lymphocytes had a lesser degree of atypia, but displayed enlarged, hyperchromatic, and irregular nuclei. The atypical lymphocytes were positive for CD3, CD8, and CD30, as well as perforin and granzyme B. The cells were negative for CD7, ALK1, and EBV-LMP1. Fluorescence in-situ hybridization for DUSP22-IRF4 rearrangement was negative. The patient was managed with topical medications and has not shown signs or symptoms of a secondary lymphoproliferative process. We present this case to raise awareness in distinguishing LYP type D from other benign and malignant mimickers, and highlight the importance of clinicopathologic correlation in this diagnosis.

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