OTHR-05. Diagnosis and Treatment of Solitary Pituitary Metastatic Cancer: A Case Series

OBJECTIVE: Metastatic pituitary carcinoma accounted for only 1% of pituitary lesions. METHODS: Patients with isolated pituitary metastatic carcinoma admitted to our hospital from 2014 to 2018 were retrospectively collected, clinical features and prognosis were analyzed. RESULTS: A total of 5 patients (4 males and 1 female) with a median age of 48 years (21 to 66 years) were included, all with single intracranial pituitary nodules as the initial clinical presentation. The related symptoms were visual impairment (5/5 cases), hypopituitarism (5/5 cases), visual field defect (5/5 cases), headache (4/5 cases), hypothyroidism (4/5 cases), diabetes insipidus (2/5 cases). All the 5 patients received surgical resection (total or partial resection) of tumors in the sellar region via nasal sphenoidal approach. Postoperative pathology confirmed that 4 cases were metastatic adenocarcinoma and 1 case was metastatic squamous carcinoma. Further imaging examinations, such as CT or whole-body PET/CT, confirmed that the primary lesions of all the 5 patients were from the lung. Gene testing indicated that 3 of the 4 adenocarcinoma patients were EGFR mutation positive and 1 of the 4 adenocarcinoma patients was ROS1 mutation positive. Patients received radiotherapy (5/5 cases), targeted therapy (4/5 cases), or chemotherapy (1/5 cases) after surgery. Survival follow-up to May 2019 showed that 4 patients had died, with a survival of 2, August, 28, and 30 months, respectively, and 1 patient was still alive with a survival of 4 months. CONCLUSION: The first clinical manifestation of isolated pituitary metastatic carcinoma is nervous system related symptoms, which is easily misdiagnosed. The most of the primary lesions are from lung, especially lung adenocarcinoma with positive driver gene. Surgery, radiotherapy combined with targeted therapy or chemotherapy can provide survival benefits for patients with pituitary metastatic carcinoma.