Pituitary metastasis: a rare condition

Tumor metastasis to the pituitary gland is a rare, not well-documented and life-threatening condition associated with a shortened life span. A better understanding of its clinical manifestations could lead to earlier diagnosis, appropriate therapy and potentially improving quality of life. Therefore, we retrospectively studied the charts of patients with pituitary metastases who were treated at the City of Hope National Medical Center (Duarte, CA) from 1984 to 2018. We reviewed and analyzed tumor origin, primary pituitary clinical manifestation, duration between primary tumor diagnosis and pituitary metastasis, type of treatment and patient survival. A total of 11 patients were identified with a mean age of 59.2 years and median survival following the diagnosis of metastasis of 10 months. Breast cancer and lymphoma were the most common primary origins in these cases, and diabetes insipidus and panhypopituitarism were the most common clinical manifestations of their metastasis. We also compared our results with reports in the literature published between 1957 and 2018. A total 289 patients with pituitary metastasis have been reported in the literature. Breast cancer was the most frequent primary origin of the metastasis, and visual symptoms were the most common primary manifestation. The posterior part of the pituitary is more susceptible than the anterior to metastasis. Pituitary metastasis may occur as a consequence of successful primary tumor treatment prolonging the chance of seeding. Future studies are needed to determine the molecular mechanism of metastasis to the pituitary.