Pituitary Melanoma Metastasis: A Case Report and Literature Review

Metastases to the pituitary gland are a rare finding, with breast and lung being the most common metastases in this anatomical region. Pituitary melanoma metastases reports are thus sparse, and both diagnosis and treatment are challenging. We present the case of a 66-year-old woman with pituitary melanoma metastasis who presented with symptoms of anterior pituitary dysfunction and headache. These symptoms were difficult to manage medically until gross total resection and immunotherapy were carried out. At 17 months post-operative, there was no progression of the underlying disease. A review of the published literature was performed for all the histologically confirmed pituitary melanoma metastases, as well as their clinical presentation, diagnosis, and treatment workout. Our literature review included 18 published cases: the median age was 62, 68% were male, and the median time of melanoma diagnosis to pituitary metastasis diagnosis was 25 months. The most common symptoms were anterior pituitary deficiency, visual disturbances, headache, cranial nerve palsy, and diabetes insipidus. In terms of management, surgery, radiotherapy, and chemotherapy were used alone or in combination. The median overall survival was 9.5 months. These metastases present a great diagnostic and therapeutic challenge since the symptoms are non-specific and there are no available treatment guidelines. Surgery to decompress the adjacent structures allows for symptomatic control and a better quality of life.