Case History
42-year-old woman with two non-ulcerated skin nodules on right arm. The lymphoid infiltrate was CD20(-), CD8(+)/CD4(-), CD56(-), CD30(-), granzyme-B(+).
What is the diagnosis?
Answer: D. Subcutaneous panniculitis-like T-cell lymphoma
Subcutaneous panniculitis-like T-cell lymphoma (SPTCL) is a T-cell lymphoma of αβ cells usually involving subcutaneous tissue with prominent karyorrhexis. Median age of diagnosis is 35 years (range 5 months to 84 years). Microscopic examination shows an atypical lymphoid infiltrate in the subcutaneous tissue. Malignant T cells have prominent atypia and rim around adipocytes. Prominent necrosis and apoptosis is characteristic. Plasma cells, eosinophils and neutrophils are scant to absent. Phenotype is CD8(+)/CD4(-), CD56(-), CD30(-), granzyme-B+. Prognosis is very good (5-year survival: 80%) except when associated with hemophagocytic syndrome.
Anaplastic large cell lymphoma forms superficial nodules (epidermis or dermis rather than subcutis) and is rarely panniculitis-like. CD30 is diffusely positive.
Cutaneous γ/δ T-Cell lymphoma is a more aggressive disease with worse prognosis that occurs in older patients (median age 60 years) and has dermal and epidermal involvement with ulceration. Immunophenotype is usually CD4(-)/CD8(-) and CD56(+).
Lupus profundus panniculitis infiltrates the subcutis in panniculitic pattern but shows plasma cells and germinal centers unlike SPTCL.
Case contributed by Diana Morlote, M.D., Hemepath Fellow, UAB Department of Pathology