[An unusually painful leg ulcer in an 81-year-old patient: an interdisciplinary challenge].

An 81-year-old male patient with a history of peripheral arterial disease (PAD) was admitted to the authors' outpatient clinic with a painful lower leg ulcer. As the degree of PAD did not correspond to the clinical findings, multiple biopsies were taken from the base and edge of the ulcer. This resulted in the histopathological and clinical diagnosis of pyoderma gangrenosum (PG). Since PG is often associated with numerous underlying diseases, further thorough examinations were performed. A mass in the gastric antrum suspicious for malignancy was histopathologically identified as gastric cancer (signet ring cell carcinoma). The PG was successfully treated with cortisone p.o. and tacrolimus ointment. Since the cancer was locally limited, the patient underwent surgery involving gastric resection with D2 lymphadenectomy and gastrojejunostomy (Roux-en‑Y anastomosis).