Abstract
INTRODUCTION: Primary cutaneous gamma-delta T-cell lymphoma (PCGDTL) is a rare and aggressive subtype of cutaneous T-cell lymphoma, often associated with poor prognosis and resistance to conventional therapies. CASE PRESENTATION: We present the case of a 91-year-old Japanese man with a 2-month history of rapidly growing, painful nodules on the face, trunk, and extremities. Histopathology showed dermal infiltration by atypical lymphoid cells positive for CD3 and CD5 but negative for cytotoxic markers such as TIA-1 and granzyme B. Flow cytometry confirmed a TCR-γδ+ T-cell phenotype. Given his advanced age, palliative radiotherapy (8 Gy in 4 fractions) was chosen. The treatment was well tolerated and led to dramatic clinical improvement without adverse effects. CONCLUSION: Although PCGDTL is known for its poor response to both chemotherapy and radiotherapy, this case illustrates the potential of localized radiotherapy as a low-toxicity option that may achieve temporary in selected elderly patients. This report contributes to the limited literature on non-chemotherapy-based management strategies for PCGDTL and highlights the importance of individualized treatment approaches in frail or super-aged patients.