Background:Pyoderma gangrenosum is a rare inflammatory disease of unknown etiology and unspecific histopathology. There are no clear-cut criteria for the diagnosis of this disease. The diagnosis is usually made based on clinical appereance, course of disease and possible, commonly coexisting disorders. In atypical cases the diagnosis is based on exclusion of other causes of similar appearing cutaneous ulcerations.Main observations:The 67-year-old male patient, presented with a 15-year history of painful ulcers and vegetative lesions covered with sero-hemorrhagic and purulent secretions, localized on the dorsal surface of both hands leading to self-amputation of distal phalanges. We report a step-by-step The patient refers to have these complaints for more than 15 years. An extensive diagnostic procedure led to the diagnosis of pyoderma gangrenosum as a diagnosis of exclusion.Conclusion:This report shows an atypical variant of an ulcerative disease. Pyoderma gangrenosum, a diagnosis of exclusion, was sustained based on an extensive diagnostic procedure. In this article we describe the step-by-step approach which let to this diagnosis.