Cutaneous T-cell lymphomas (CTCLs) characterized by infiltration of the skin of T-cell lymphocytes represent an uncommon and rare subset of extranodal non-Hodgkin lymphomas. Primary CTCL, not otherwise specified, is among the most important subtypes of CTCLs characterized by rapid cutaneous dissemination and systemic involvement. Herein, we present a case of primary CTCL, not otherwise specified, diagnosed via 18 F-FDG PET/CT after initial misdiagnosis of cutaneous leishmaniasis.