Persistent pigmented purpuric eruption associated with mycosis fungoides: a case report and review of the literature

Abstract A purpuric eruption may be an unusual early manifestation of mycosis fungoides (MF). On the other hand, persistent pigmented purpuric dermatoses (PPPD) may, occasionally, evolve to cutaneous T‐cell lymphoma. Coexistence of these two conditions has been reported, but it is extremely rare. We present the case of an elderly woman with a long‐standing pruritic, pigmented purpuric eruption. On 1‐year follow‐up, histological features suggesting early MF were observed and molecular analysis of the rearrangement of T‐cell receptor genes revealed clonality. Our patient may represent a case of PPPD evolving to MF, a case of MF clinically featuring PPPD, or an intermediate condition in a nosological continuity extending from PPPD to MF. A persistent pigmented purpuric eruption may rarely be a harbinger of cutaneous T‐cell lymphoma. Therefore, vigilant long‐term follow‐up of PPPD is highly recommended.