Non-Neoplastic Dermatopathology

263

5.7 Lupus Panniculitis vs Subcutaneous Panniculitis-Like T-Cell Lymphoma

Subcutaneous Panniculitis-Like T-Cell Lymphoma Neoplastic T-cell lymphocytes show CD3 + , CD4 − , CD8 + , CD56 − immunoprofile with expression for cytotoxic markers including granzyme B, TIA1, and perforin. Ki-67 hotspots may also help to distinguish from lupus panniculitis. The lymphocytes are TCR beta F1 positive and TCR gamma-1 negative. High-dose systemic corticosteroids generally result in long-term remission. Chemotherapy and stem cell transplantation may be necessary for aggressive, refractory, or recurrent cases.

Lupus Panniculitis

Special studies

Immunohistochemistry shows admixed CD4 + and CD8 + T cells with aggregates of CD20 + B cells. T-cell receptor (TCR) gene rearrangement generally polyclonal.

Treatment

Administration of antimalarial drugs, such as hydroxychloroquine, is first-line therapy. Short-term systemic corticosteroids may be added. Steroid-sparing immunosuppressive agents, such as methotrexate, azathioprine, or cyclophosphamide, may be added for severe disease or those cases associated with systemic symptoms. Chronic, relapsing course. Patients may have concomitant discoid or systemic lupus erythematosus. May lead to lipoatrophy and calcinosis, which may be severe and cause disfigurement.

Prognosis

Generally indolent course. Occasionally shows spontaneous resolution. Extension to lymph nodes and visceral organs is rare. Cases with hemophagocytic lymphohistiocytosis have worse prognosis.

Figure 5.7.1 Lupus panniculitis. Lobular inflammatory infiltrate with extension along the deep vascular plexus in the reticular dermis and around adnexae. Note hyalinization of subcutis. Figure 5.7.2 Lupus panniculitis. Infiltrate of lymphocytes and plasma cells around the eccrine unit. Copyright © Wolters Kluwer, Inc. Unauthorized reproduction of the content is prohibited. 2023

SUBCUTIS

5 DISORDERS OF THE