Superficial granulomatous pyoderma: a localized vegetative form of pyoderma gangrenosum.

Twenty-five patients had superficial ulcerative and vegetative pyoderma with granulomatous histologic findings. Healing occurred without systemic corticosteroid therapy in all but three patients. All patients had clinical pyoderma gangrenosum. In five patients the lesion occurred after surgery of the skin. Histopathologic study of 40 biopsy specimens showed focal neutrophilic abscesses of the papillary dermis, often with peripheral palisading histiocytes and foreign-body giant cells. Pseudoepitheliomatous, vegetative hyperplasia and sinus tract formation were observed frequently. All patient had massive areas of plasmacytosis, and 13 had eosinophils. Granulation tissue, hemorrhage, and fibrosis were additional features in some areas. Foreign material in the lesions was considered unimportant, except in one patient with a starch granuloma. Therapy with local corticosteroids, minocycline, tetracycline, or sulfa drugs resulted in healing in 15 patients. We believe that we have identified a localized, limited form of chronic superficial pyoderma gangrenosum with verrucous and ulcerative lesions and a granulomatous histologic appearance that represents a unique pattern of this disease in some patients.