Granulomatous slack skin - seven years follow-up of a case with features of "parapsoriasis en plaques", muscle involvement, granulomatous vasculitis, and necrobiotic changes.

Granulomatous slack skin (GSS) represents an extremely rare variant of mycosis fungoides with only 70 cases reported in the literature to date. It is characterized clinically by the occurrence of bulky, pendulous skinfolds, usually located in flexural areas and histologically by an infiltrate composed of small neoplastic T-lymphocytes joined by granulomatous inflammation with scattered multinucleated giant cells containing nuclei arranged in a wreath-like fashion. Since its first description, very rare cases of GSS with muscle involvement, large vessels involvement, or necrobiotic changes have been reported. We present an extraordinary case of GSS with all these unusual features developing in the lesions of the same patient. The long follow-up of seven years allowed us to document the evolution of each lesion. Some lesions appeared and evolved in a manner very reminiscent of those of "parapsoriasis en plaques", others were classical GSS lesions, and still others developed large ulcerated lesions. These ulcerated lesions consistently failed to respond to conventional wound therapy, skin directed therapy [retinoids + psoralen combined with ultraviolet A (PUVA)-therapy], and interferon-alpha therapy. Remarkably, the ulcers completely healed when systemic corticosteroids were added. We hence postulate that the ulcers appeared because of large vessel vasculitis rather than tumoral direct destruction.