Indolent primary cutaneous γ/δ T-cell lymphoma localized to the subcutaneous panniculus and its association with atypical lymphocytic lobular panniculitis.

The 2005 classification of lymphoma proposed the designation of subcutaneous panniculitis-like T-cell lymphoma exclusively for those tumors composed of α/β neoplastic cells. Subcutaneous lymphomas that comprised γ/δ T cells are termed primary cutaneous γ/δ T-cell lymphoma. The different clinical outcomes justified this separation; a more indolent course was characteristic of the α/β variants vs the poor 5-year survival of the γ/δ forms. We describe 5 patients with γ/δ T-cell lymphoma localized to the subcutis with a less aggressive clinical course. Two patients were alive 5 years after presentation, and in the remaining 3, the disease is in complete remission after simple intervention. Three patients had a waxing and waning phase, likely representing a prelymphomatous phase, which then progressed to an overt malignant tumor. Therefore, it is important to recognize that not all patients with γ/δ T-cell lymphomas have a poor prognosis.