-Case Reports-

Lupus Erythematosus Tumidus with Pseudolymphomatous Infiltrates: A Case Report

Yuki Umeda¹, Keigo Ito², Shinichi Ansai², Toshihiko Hoashi³, Hidehisa Saeki³ and Naoko Kanda¹

¹Department of Dermatology, Nippon Medical School Chiba Hokusoh Hospital, Chiba, Japan
²Department of Dermatology, Nippon Medical School Musashi Kosugi Hospital, Kanagawa, Japan
³Department of Dermatology, Nippon Medical School, Tokyo, Japan

A 39-year-old Japanese woman presented with a pruritic infiltrated erythematous plaque on the right cheek. Histopathologic analysis of the erythema showed dermal edema, separation of collagen bundles, and nodular perivascular and periadnexal infiltration of lymphocytes in the whole dermis, without epidermal changes. Alcian blue staining intensity was elevated between the collagen bundles, indicating dermal mucinosis. The nodular infiltrates consisted of CD3+ T cell clusters and CD20+ B cell clusters (ratio, approximately 3:1) and included numerous CD123+ cells, indicative of plasmacytoid dendritic cells. Blood analysis revealed serum antinuclear antibody at a titer of 1:160 (homogeneous, speckled pattern). Lupus erythematosus tumidus with pseudolymphomatous infiltrates was diagnosed. Hydroxychloroquine treatment partially improved symptoms; however, the addition of prednisolone was required for complete resolution. Lupus erythematosus tumidus is sometimes accompanied by pseudolymphomatous infiltrates. Dermal mucinosis and the presence of numerous plasmacytoid dendritic cells are useful in differentiating lupus erythematosus tumidus from pseudolymphoma.

J Nippon Med Sch 2020; 87: 100-103

Keywords
lupus erythematosus tumidus, pseudolymphoma, mucinosis, plasmacytoid dendritic cell

Correspondence to
Naoko Kanda, MD, PhD, Department of Dermatology, Nippon Medical School Chiba Hokusoh Hospital, 1715 Kamagari, Inzai, Chiba 270-1694, Japan
n-kanda@nms.ac.jp

Received, November 27, 2019
Accepted, December 25, 2019