From circumscribed scleroderma (morphea) to subcutaneous panniculitis-like T-cell lymphoma: case report.

Subcutaneous panniculitis-like T-cell lymphoma is a rare form of non-Hodgkin lymphoma. It presents clinically as panniculitis, with erythematous, firm subcutaneous infiltrates and recurrent papulonodules. A 45-year-old male Croat presented with a 6-month history of tender erythematous subcutaneous skin lesions without systemic symptoms. Analysis of a lesion biopsy specimen showed circumscribed scleroderma (morphea). During hospitalization, skin biopsies from two subcutaneous lesions on the stomach were repeated, and pathohistologic analysis corresponded primarily to panniculitis in the context of morphea. Pathohistologic analysis and immunohistochemistry of a specimen obtained by tumor excision from the back indicated subcutaneous panniculitis-like T-cell lymphoma. Histologic analysis revealed a dense infiltrate of atypical T-lymphoid cells expressing CD8(+) phenotype located in the subcutaneous tissue with histiocyte-phagocytizing apoptotic cells. Specific hematologic analysis and medical treatment were continued. This case report illustrates the importance of continuous follow-up with repeat biopsy and use of immunohistologic techniques for early diagnosis.