Pyoderma gangrenosum (PG) is rather rare chronic dermatosis presenting as cutaneous necrosis followed by development of expanding chronic ulcer with well-demarcated, undermined, violaceous borders. Diagnosis of PG is predominantly based on the clinical presentation and course. Histopathologic findings may be non-specific. Half of patients suffer from a somatic systemic disease. We describe 92-year-old lady presenting with large non-healing ulcer of the anterolateral calf with the diagnosis of atypical PG. In a discussion differential diagnosis of cutaneous ulcers mimicking PG is reviewed and the treatment possibilities summarised.