Leptomeningeal Dissemination in Patients with Pituitary Metastasis from Breast Cancer

Pituitary metastases are uncommon complications of systemic cancer and account for only 1% of pituitary lesions. Breast cancer is one of the most common tumors to metastasize to the pituitary gland. A multidisciplinary approach that calls for close collaboration among oncologists, neurosurgeons, radiologists, and endocrinologists is mandatory for diagnosis and treatment of pituitary metastasis. From 2002 through 2013, 6 patients with pituitary metastases were treated at Shizuoka Cancer Center Hospital. The patients' age at presentation ranged from 45 to 75 years (average 59 years). Five of 6 patients had symptoms: anterior pituitary insufficiency in 4, diabetes insipidus in 3, and visual deficits in 2 patients. Five patients had other metastases at the time of presentation. Local irradiation to the metastatic lesion was adopted in 4, and whole brain irradiation was in 2 patients. In all cases, local control was achieved after irradiation, however, the pituitary insufficiency did not recover. Two of 4 patients treated with local irradiation suffered from meningeal dissemination within 5 months after treatment, and died at 8 and 11 months after diagnosis of pituitary metastasis, respectively. The patients treated with whole brain irradiation had longer survival periods. Early diagnosis, endocrinological management, and radiation therapy improve the quality of life in patients suffering from pituitary metastasis. Whole brain irradiation may be favorable in order to prevent meningeal dissemination.