Progressive visual disturbance and enlarging prolactinoma caused by melanoma metastasis: A case report and literature review

RATIONALE: Melanoma metastases to the pituitary adenoma (MMPA) are extremely rare, with only 1 reported case. To date, the melanoma metastasis to the existing prolactinoma has not been reported in literatures. PATIENT CONCERNS: We report a case of 62-year-old woman presented with progressive visual disturbance and hyperprolactinemia. Magnetic resonance imaging demonstrated the presence of a round sellar mass. DIAGNOSES: Melanoma metastasis to the pituitary adenoma. INTERVENTIONS: Surgery was performed and intraoperative frozensection examination found melanin granules and histopathological examination confirmed melanoma metastasis to the pituitary adenoma. OUTCOMES: After surgery, the patient developed widespread melanoma metastasis to lower limbs. Twenty-two months later, the patient was alive with worse symptoms. LESSONS: We reviewed and analyzed the clinical data, imaging features, and treatment methods of other reported cases of metastases to pituitary adenoma (MPA). This study provides clinical information for the diagnosis and management of MMPA.