Unusual Presentation of Subcutaneous Panniculitis-Like T-Cell Lymphoma.

Subcutaneous panniculitis-like T-cell lymphoma (SPTCL) is a rare variant of primary cutaneous T-cell lymphoma primarily affecting subcutaneous adipose tissue and mimicking lobular panniculitis. It often presents with erythematous subcutaneous nodules or plaques, and diagnosis can be challenging due to its diverse clinical manifestations. We report an unusual presentation of SPTCL in a 40-year-old female with recurrent, painless ulcerated plaques on the thighs and lower legs, accompanied by systemic symptoms including weight loss, fatigue, and laboratory abnormalities. Initially misdiagnosed as erythema nodosum, the patient was treated with antibiotics and corticosteroids without significant improvement. Histopathology and immunohistochemistry from skin biopsies revealed atypical lymphocytic infiltration consistent with SPTCL (CD3+, CD30+, CD4+, CD8-, CD56-). This case adds to the spectrum of SPTCL presentations, emphasizing the importance of considering SPTCL in panniculitis-like lesions refractory to conventional treatment. Prompt histopathological evaluation with immunophenotyping is crucial for early diagnosis and appropriate management to improve patient outcomes.