Two Atypical Cases of Cutaneous Gamma/Delta T-Cell Lymphomas

Cutaneous γ/δ T-cell lymphoma (CGD-TCL) is a recent entity described in the newly revised World Health Organization-European Organization for Research and Treatment of Cancer classification of cutaneous lymphomas, and is characterized by the γ/δ T-cell receptor expression on atypical lymphocytes. Only a few cases of primary CGD-TCL have been reported, with an extremely aggressive course (median survival time of 15 months). We describe 2 atypical cases of CGD-TCL. The first case was initially misdiagnosed as an inflammatory panniculitis due to the granulomatous infiltrate on the skin biopsy specimen. Diagnosis was confirmed using δ PCR that revealed γ/δ T-cell clonal expansion. The evolution was marked by predominant γ/δ T-cell infiltrate with diffuse body fat involvement as seen on positron emission tomography-computed tomography. The second case is the first described Epstein-Barr virus (EBV)-associated CGD-TCL with a rapidly fatal evolution. CGD-TCL is also a heterogeneous entity and δ PCR and EBV-encoded RNA probe to detect an EBV latent infection may help diagnose and characterize these cutaneous lymphomas.