This article touches upon topical problems of modern medicine, representing the difficulty of timely diagnosis of oncological diseases of arduous localization and management of patients with malignant neoplasms. As an example, a clinical case of primary urethral melanoma is presented, illustrating a complex of aspects associated with the rarity of detecting malignant neoplasms of a given localization. The creation of standardized tactics for managing patients with rare malignant tumors and the correct interpretation of research results at the diagnostic stage, play an important role in improving the quality and life expectancy of patients. A step-by-step analysis of difficult situations will increase the alertness of doctors of all specialties.