Cytotoxic gamma/delta subcutaneous panniculitis-like T-cell lymphoma: report of a case with pulmonary involvement unresponsive to therapy.

Peripheral subcutaneous panniculitis-like T-cell lymphoma (PSPTCL) is a rare form of cutaneous lymphoma recently proposed as a distinct clinicopathological entity. It usually presents with multiple indurated subcutaneous plaques or tumours, most commonly located on the extremities and trunk and clinically mimicking lobular panniculitis. Associated constitutional symptoms due to haemophagocytic syndrome may advance or, more often, complicate the clinical course in about 40-70% of cases. Finding of TIA-1+ and perforin + cytolytic granules in atypical pleomorphic lymphocytes suggests PSPTCL origin from granular cells of T-cell or natural killer cell phenotype. Cells have a CD3+ CD4+ CD8- or CD3+ CD4- CD8+ T-cell phenotype. Moreover, these lymphomas can express natural killer cell associated antigens, such as CD56, especially in gamma/delta variants. PSPTCL following an indolent clinical course with recurrent self-healing lesions have been described. The prognosis of most PSPTCL is poor even when treated with aggressive chemotherapy. This paper reports a case of PCTCL in a young woman with T-cytotoxic differentiation, with rapid progression unresponsive to several treatments.