SUN-918 A Brain Metastasis in Malignant Paraganglioma Treated with Multidisciplinary Strategy

Introduction: The most common sites of metastatic pheochromocytoma/paraganglioma (PPGL) are regional lymph nodes, bone, liver, and lung. Metastatic PPGL to the brain is very rare. Herein we describe a case of malignant paraganglioma (PGL) with a brain metastasis in the 27th year of his clinical history. Clinical Case: A 57-year-old Japanese man presented with sudden onset of headaches, speech disturbance, and mild cognitive impairment. His medical history was significant for surgery to resect a left peri-adrenal PGL at 30 years of age. At 35 years of age small lung metastases were treated with 5 cycles of chemotherapy without demonstrable response. Hypertension was diagnosed at age 44 years and diabetes mellitus at 49 years of age. The some lung metastases gradually increased in size and he underwent video-assisted thoracic surgery (VATS) at age 50 years. Plasma norepinephrine (pNE) and urine normetanephrine (uNM) levels, which were 3-fold elevated above the upper limit of the reference ranges, normalized after VATS. Subsequently, hypertension was well controlled and pNE and uNM levels remained within the reference ranges. Then, at 57-years of age, he developed central nervous symptoms and a mass with broad peritumoral edema was found in his left parietal lobe on head MRI. The 1.6 cm mass was hypervascular and isointense on T1-weighted imaging and was an inhomogeneous high-intensity in T2-weighted imaging. Both 123-I-MIBG SPECT and 18F-FDG-PET/CT imaging showed strong uptake in the brain metastasis. Although pNE and uNM levels were within their respective reference ranges, the 123-I-MIBG was diagnostic of metastatic PGL. Dexamethasone (DEX) was started to improve the brain edema. The brain metastasis was treated with linear accelerator stereotactic radiosurgery (LINAC-SRS) which was tolerated well without any adverse effects. However, the tumor volume and peritumoral edema area had not decreased one year after LINAC-SRS. Because high dose of DEX needed to continue, and his drug-induced psychiatric symptoms had worsened, we decided to move to surgical option. A craniotomy and total tumor removal was performed without any perioperative event. His condition rapidly improved and the DEX treatment was discontinued after surgery. Although he had slight hemiplegia and aphasia, and small lung metastases, he maintained a stable disease three years after surgery. Conclusion: Because PPGLs are slow growing neoplasms, multidisciplinary treatment should be considered even though there are multiple metastases. SRS has been used to treat skull base and neck PGLs with local control rates >90%. However, although SRS could suppress tumor growth, dramatic tumor volume reduction is not expected. Therefore surgical approach should be considered for brain metastasis as the next strategy for intracranial decompression.