Primary Cutaneous Gamma‐Delta T‐Cell Lymphoma With Unusual Clinicopathological Characteristics: A Study of Three Patients With Molecular Characterization

Primary cutaneous gamma-delta T-cell lymphoma (PCGDTCL) is a rare cytotoxic lymphoma with considerable clinicopathological heterogeneity. We report three patients with unusual presentations, including a TCR-silent phenotype with spontaneous regression followed by rapid progression, a granulomatous variant with a prolonged indolent course, and a lupus panniculitis-like form. Molecular studies demonstrated persistent clonal disease and identified recurrent alterations involving TET2, STAT3, CDKN2A, MAPK1, PDCD1 and TNFAIP3, with acquisition of additional mutations during disease evolution. These cases expand the recognized spectrum of PCGDTCL and highlight the importance of integrating clinicopathological and molecular findings in diagnostically challenging presentations.