Tehran University of Medical Sciences Acta Medica Iranica 0044-6025 60 12 2023 01 30 782 784 Nadezhda V Maksimova Department of Endocrinology, Pirogov Russian National Research Medical University, Moscow, Russia. AND Central Clinical Hospital of the Administrative Directorate of the President of the Russian Federation, Moscow, Russia Aleksey O Kovylov State Moscow Endocrine Dispensary, Moscow, Russia Mikhail E Krasheninnikov Research and Educational Resource Center for Cellular Technologies, Peoples' Friendship University of Russia (RUDN University), Moscow, Russia Marina V Kovina Research and Educational Resource Center for Cellular Technologies, Peoples' Friendship University of Russia (RUDN University), Moscow, Russia . Alexey V Lyundup Research and Educational Resource Center for Cellular Technologies, Peoples' Friendship University of Russia (RUDN University), Moscow, Russia . AND N.P. Bochkov Research Center for Medical Genetics, Moscow, Russia Denis S Baranovskii Research and Educational Resource Center for Cellular Technologies, Peoples' Friendship University of Russia (RUDN University), Moscow, Russia . AND Department of Regenerative Medicine, National Medical Research Radiological Center, Obninsk, Russia Ilya D Klabukov Research and Educational Resource Center for Cellular Technologies, Peoples' Friendship University of Russia (RUDN University), Moscow, Russia . ANDDepartment of Regenerative Medicine, National Medical Research Radiological Center, Obninsk, Russia. AND Obninsk Institute for Nuclear Power Engineering, National Research Nuclear University MEPhI, Obninsk, Russia 2022 07 18 2022 12 11 Malignant skin ulcerations may mimic diabetic foot ulcers leading to misdiagnosis. In this case report, we discuss an uncommon but severe problem of malignant tumors initially misdiagnosed as diabetic foot ulcers, underlying the need to improve medical awareness, diagnostics, and approaches for therapy once the correct diagnosis is made. We describe the case of an 82-year-old male with diabetes mellitus and melanoma metastases initially misdiagnosed as diabetic foot ulcers. In diabetic patients, several skin disorders may coexist on the same foot, including actual diabetic foot ulcers and skin cancers. Among multiple skin disorders that coexist on the foot of a diabetic patient, the skin metastases may be misdiagnosed as diabetic foot ulcers. Significant efforts should be made to create new non-invasive, rapid diagnostic techniques to eliminate misdiagnoses of skin disorders in diabetic patients. https://acta.tums.ac.ir/index.php/acta/article/view/10256