Primary Malignant Melanoma of the Endometrium: A Case Report.

Introduction: Malignant melanoma most commonly occurs in the skin. Primary malignant melanoma of endometrium is quite rare. Its diagnosis depends on clinical characteristics and pathological examination. It usually exhibits high degree of tumor histology, early onset of distant metastases, and unfavorable prognoses. Case Presentation: In this paper, we report a case of a 73-year-old woman with primary malignant melanoma of endometrium. This patient denied a history of nevus removal or any family medical history of cancer. She was admitted to the hospital for irregular vaginal bleeding after menopause and performed an endometrial biopsy. Pathological of the scrapings suggested malignant melanoma. She subsequently underwent a radical surgery. The final pathology diagnosis was primary malignant melanoma of endometrium, and BRAF gene mutation was detected. The tumor staged as IVB according to the International Federation of Gynecology and Obstetrics (FIGO) classification. Thus, she then started adjuvant chemotherapy. This patient is currently on oral targeted therapy and is still being followed up. Conclusion: Mucosal melanoma is infrequent, and primary malignant melanoma of endometrial is a rare subtype. To the best of our knowledge, malignant melanoma originating from endometrium has never been reported before. It has a high degree of malignancy and is prone to early metastasis. Further investigations are warranted to explore its underlying pathogenesis, management, and outcomes.