CMET-10. INTRACRANIAL SOLITARY PITUITARY METASTASIS: THE IMPLICATIONS FROM FIVE CASES

Abstract

BACKGROUND: Pituitary gland metastasis is a rare disease which represents only 1% of pituitary gland lesions. Intracranial solitary pituitary metastasis tends to be misdiagnosed as pituitary adenoma, resulting in a delayed anti-tumor treatment. METHODS: Five cases of patients with pituitary gland metastasis recorded between 2014 and 2018 in our hospital were investigated with reference to patient demographics, symptoms at presentation, radiological and histological findings, management and outcomes. RESULTS: Five patients (4 male and 1 female) were included and the median age was 48 years (range: 21 to 66). In those five cases, central nervous system related symptoms were the first sign of malignancy, including visual loss (5 in 5 patients), visual field defects (5 in 5 patients), apituitarism (5 in 5 patients), headache (4 in 5 patients), hypothroidism (4 in 5 patients) and diabetes insipidus (2 in 5 patients). All patients received total or partial hypophysectomy and pathologically revealed metastatic adenocarcinoma in 4 patients and metastatic squamous carcinoma in 1 patient. Further examinations by Computed Tomography (CT) or Positron Emission Computed Tomography (PET) indicated lung as primary site in five cases. EGFR mutation and ROS1 fusion were found in 3 and 1 adenocarcinoma patient, respectively, through gene detection of tissue. Postoperative radiotherapy (5 patients), target therapy (4 patients) and chemotherapy (1 patient) were given as subsequent treatment. During the follow-up, four patients died and the overall survival was 2, 8, 28 and 30 months, respectively. CONCLUSION: We found that pituitary symptoms usually presented as the first sign of malignancy in intracranial solitary pituitary metastasis. Lung is the most frequently primary site, particularly in adenocarcinoma with driver gene mutation. Patients may benefit from multidiscipline treatment, including resection of pituitary metastasis combined with radiotherapy and targeted therapy.