Gamma/delta T‐cell lymphoma with mycosis fungoides‐like clinical course transforming to “T‐cell‐receptor‐silent” aggressive lymphoma: Description of one case

Primary cutaneous γδ T‐cell lymphomas (PCGDTLs) are a heterogeneous group of lymphomas representing about 1% of primary cutaneous T‐cell lymphomas (CTCLs) and mostly regarded as clinically aggressive. Current WHO‐EORTC classification recognizes different clinic‐pathologic subsets of PCGDTL, but it suggests that cases showing a mycosis fungoides (MF)‐like clinical presentation and histopathology should be classified as MF irrespective of phenotype for their indolent course. Herein, we describe a case of γδ‐MF, featuring at onset a granulomatous pattern, with subsequent clinical worsening signaled by the development of an ulcero‐necrotic lesion and systemic dissemination, leading to death in 5 months. Clinical progression was sustained by a shift to mature T‐cell lymphoma composed of medium to large‐sized blastoid T‐cells featuring a T‐cell receptor (TCR) silent immunophenotype.