[Granulomatous mycosis fungoides histologically simulating cutaneous sarcoidosis]

Granulomatous mycosis fungoïdes is an uncommon mycosis fungoïdes. We report a misleading case initially thought to be cutaneous sarcoidosis.

A 34-year-old man developed stationary erythematous plaques on the trunk and members. Pathology reported a sarcoidal aspect. No extracutaneous sarcoidal lesions were found. The lesions resolved with puvatherapy. Five years later, the patient developed a voluminous skin tumor in the scapular area. Pathology reported granulomatous mycosis fungoides. Radiotherapy was given. Other plaques developed on the skin with the same histological aspect as initially and disappeared after local applications of chlormethine. During the clinical course, the patient developed visceral localizations of mycosis fungoides in the abdomen and pelvic nodes which responded to polychemotherapy.

Histologically, granulomatous mycosis fungoïdes is defined as the association of epidermotropic T-cell lymphoma with epitheloid and giant cell dermal granulomas and no necrosis. Variants may be misleading when the epitheloid and giant cell aspect predominates, as in our observation. An analysis of 28 reported cases showed no disinction between the clinical features. Clinical course or treatment for granulomatous fungoides mycosis or classical fungoid mycosis. Extracutaneous sarcoidosis is rarely associated. Most likely, there is a tissue reaction to the lymphona.