Background: Granulomatous mycosis fungoides is an extremely rare type of cutaneous T-cell lymphoma. Two cases are described and checked for clinical, histological and therapeutic differences to other variants of mycosis fungoides.
Case reports: Case 1: a 52-year-old patient with livid plaques covering the whole integument. Histological findings showed granulomas with multinuclear giant cells in addition to a malignant lymphohistiocytic infiltrate (monodonal T-cell receptor (TCR)-gamma rearrangement). Despite various chemotherapeutic regimens, progression to tumour stage was observed. Case 2: an 88-year-old man with plaques and ulcerating tumours on the trunk and head. Histological findings showed malignant T-lymphocyte infiltrate (monoclonal TCR-gamma rearrangement) and granulomas with multinuclear foreign-body giant cells. Complete regression of all lesions was achieved using both local psoralen-ultraviolet A and electron radiotherapy.
Conclusions: The diagnosis of a granulomatous mycosis fungoides depends exclusively on the histological demonstration of granulomas. Distinct clinical characteristics are not present. Apart from granuloma formation, no other noticeable histological features are evident. The presence of granulomas in mycosis fungoides does not have prognostic implications, as cases with aggressive, but also with a prolonged course have been described.