Background: Oral mucosal melanoma (oral malignant melanoma—OMM) is a rare malignant neoplasm. It arises from the proliferation of atypical melanocytes—cells derived from the neural crest that produce melanin. Unlike cutaneous melanomas, which are etiologically linked to ultraviolet (UV) radiation exposure, the risk factors for mucosal melanomas remain poorly defined. According to the World Health Organization (WHO), these tumors predominantly affect older individuals, with peak incidence occurring in the seventh decade of life and are rarely observed in the first three decades. The primary treatment modality for patients with mucosal melanoma is radical surgical excision with clear margins. The 5-year overall survival rate for OMM ranges from 20% to 50%. Case Presentation: This article reports an atypical clinical manifestation of oral mucosal melanoma in a 99-year-old patient who presented to the Department of Oral Surgery at the University Dental Center, Medical University of Warsaw. The nonspecific clinical appearance did not initially suggest a melanocytic lesion. A definitive diagnosis was established through histopathological examination, which subsequently guided the treatment plan. Conclusions: This report highlights the necessity of performing microscopic evaluation even for lesions with a nonspecific or non-suspicious appearance, underlines the importance of regular dental check-ups, and stresses the need to strengthen oncological vigilance among dental practitioners.

Background: Oral mucosal melanoma (oral malignant melanoma – OMM) is a rare malignant neoplasm. It arises from the proliferation of atypical melanocytes—cells derived from the neural crest that produce melanin. Unlike cutaneous melanomas, which are etiologically linked to ultraviolet (UV) radiation exposure, the risk factors for mucosal melanomas remain poorly defined. According to the World Health Organization (WHO), these tumors predominantly affect older individuals, with peak incidence occurring in the seventh decade of life and are rarely observed in the first three decades. The primary treatment modality for patients with mucosal melanoma is radical surgical excision with clear margins. The 5-year overall survival rate for OMM ranges from 20% to 50%. Case presentation: This article presents a case of an atypical clinical manifestation of oral mucosal melanoma in a 99-year-old patient who came for a visit to the Department of Oral Surgery at the University Dental Center of the Medical University of Warsaw. The nonspecific clinical appearance did not initially suggest a melanocytic lesion. A definitive diagnosis was established through histopathological examination, which guided the subsequent treatment plan. Conclusion: The report emphasizes the necessity of performing microscopic evaluation even for lesions that do not appear suspicious, the importance of regular dental check-ups, and the need to enhance oncological vigilance among dental practitioners.