Subcutaneous Panniculitis-like T-cell Lymphoma

Subcutaneous Panniculitis-like T-cell Lymphoma

Aaron Auerbach, MD, PhD

This clinical photograph shows a single nonulcerated subcutaneous nodule on the arm of a 35-year-old patient. Upon excision, the nodule was diagnosed as SPTCL. (Courtesy M. Tomaszewsky, MD.)

Low-power view of SPTCL shows malignant T cells confined to subcutaneous tissue image. The dermis image and epidermis image are both spared and are morphologically unremarkable. (Courtesy M. Tomaszewsky, MD.)



  • Subcutaneous panniculitis-like T-cell lymphoma (SPTCL)


  • T-cell lymphoma of αβ cells involving subcutaneous tissue with prominent karyorrhexis and cytotoxic phenotype

    • Cases composed of γδ cells are reclassified as cutaneous γδ T-cell lymphoma in the WHO Classification of Hematopoietic and Lymphoid Tumors

    • Subcutaneous T-cell lymphomas of γδ type are more aggressive than αβ cases


Autoimmune Disease

  • Autoimmune disease present in ˜ 20% of patients

    • Systemic lupus erythematosus (SLE) most common

      • Microscopic findings of SPTCL overlap with lupus profundus panniculitis

Viral Infection

  • Rarely, SPTCL is seen with Epstein-Barr virus infection

    • May be due to immunosuppression



  • Incidence

    • < 1% of all non-Hodgkin lymphoma

      • Presents sporadically without familial involvement

  • Age

    • Median: ˜ 35 years (range: 5 months to 84 years)

      • 20% < 20 years old

      • Rarely, children < 2 years old

  • Gender

    • Men = women

  • Ethnicity

    • No ethnic predisposition


  • Extremities and trunk most common

  • Uncommonly disseminates

    • Can involve lymph nodes, but not at initial diagnosis


  • Single or multiple erythematous subcutaneous nodules or plaques

    • Painless mass, rarely ulcerates

    • Symptoms due to mass effects

  • B symptoms in up to 50%

    • Diagnosis often not discovered until months to years after onset of symptoms

  • Hemophagocytic syndrome (HPS) in up to 20%

    • Related to release of cytotoxic molecules

    • May occur up to 5 years after presenting diagnosis

Laboratory Tests

  • Cytopenias (anemia, leukopenia, thrombocytopenia)

  • ↑ liver function tests

  • ↑ erythrocyte sedimentation rate, ↑ C-reactive protein


  • Surgery

    • Sometimes excision of single lesion with no further recurrence

  • Immunosuppressive agents

    • Often given, at least initially

    • High-dose systemic corticosteroids

  • Chemotherapy

    • Recurrence or resistant cases treated with CHOP or CHOP-like therapy

  • Radiation

    • Sometimes for localized disease

  • Stem cell transplant

    • Can be considered for refractory/recurrent disease


  • Indolent disease

    • 5-year overall survival ˜ 80%

    • Mostly stage I (confined to skin)

    • Rare systemic spread

      • Including lymph nodes

      • Often years after diagnosis

  • HPS poor prognostic indicator

    • Medium survival ˜ 2 years


CT Findings

  • Enhancing nodules in subcutaneous tissue


Histologic Features

  • Atypical T-cell infiltrate of subcutaneous fat lobules

    • Involves lobules, usually spares septa

      • Uncommon septal pattern represents spilling of T cells from lobules

      • Typically, no tumor in overlying dermis or epidermis

    • Malignant T cells rim individual adipocytes

      • Characteristic, but not specific for SPTCL

    • Neoplastic cells

      • Small to large in size

      • Mild to marked atypia with irregular nuclear contours

      • Hyperchromatic nuclei

      • Pale, clear cytoplasm

  • Karyorrhexis (apoptosis) and fat necrosis characteristic

    • Necrosis from released cytotoxic molecules

  • Initial biopsy commonly shows minimal T-cell atypia

    • Later biopsies show more atypia

  • Angioinvasion in some cases

    • Poor prognostic indicator

  • Reactive inflammatory cells

    • Histiocytes

      • Vacuolated foamy cytoplasm from imbibed material/lipid

      • Erythrophagocytosis or cytophagocytosis

      • Sometimes poorly formed granulomas with multinucleated giant cells

    • Usually lacks plasma cells, eosinophils, or neutrophils



  • T-cell antigens (+) (CD2, CD3, CD5, CD7)

    • May lack 1 or more T-cell antigens

  • CD8(+)/CD4(−) in > 95% of SPTCL

    • CD4(−)/CD8(−) and CD4(+)/CD8(−) rarely

  • TCR-βF1(+), TCR-δ-1(−) (alpha-beta T cells)

  • Cytotoxic markers (+) (perforin, TIA1, and granzyme)

    • But GZM-M negative, unlike other T-cell lymphomas

  • CD56(−), CD30(−), Bcl-2(−)


  • No specific cytogenetic abnormalities

Jul 8, 2016 | Posted by in PATHOLOGY & LABORATORY MEDICINE | Comments Off on Subcutaneous Panniculitis-like T-cell Lymphoma

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