Objective: To present a rare case of giant malignant paraganglioma in liver mimicking hepatic cancer.
Methods: A 40-year-old male with a large hepatic mass was admitted to PUMC hospital in 2017.
Results: The patient had a surgical history of left adrenal incidentaloma (7.9cm×6.6cm) diagnosed pheochromocytoma by pathology in 2006. He was admitted to the hospital due to lose weight in 2016. The CT scan showed a large tumor mimicking hepatic cancer in liver（Figure 1）. His Bp was 130/80 mmHg. When he was accepted cholecystectomy and his blood pressure was suddenly elevated into 260/? mmHg during the operation. After then he move forward to PUMC hospital for the diagnosis and treatment in November, 2016. He has paroxysmal hypertension by 220-230/150-160mmHg. The urinary catecholamines and NMNs levels were very high such as DA 503.4μg/24h, NE 1023.9μg/24h, E 5.7μg/24h, NMN 1600.0μg /24h and MN 173.0μg/24h. The PET/CT showed a large aggressive mass (7.8cm×8.0cm×8.4cm) in his liver and 131I- MIBG image was positive. He was diagnosed as hepatic paraganglioma and taken the surgery by successful resection of tumor and middle liver part (Figure 2) after phenoxybenzamine therapy for 3 weeks. The hepatic malignant paraganglioma was confirmed by pathology and immunohistochemical staining: Melan-A(-)，AFP(-)，Calretinin(-)，CAM5.2(-)，CgA(+)，CK7(-)，Ki-67(index2 %) but SDHB gene mutation was not been found in this patient. At 6 months after operation, his blood pressure is 120/80 and the urinary NE 17.6μg/ 24h, E 2.0μg/24h, DA 159.2μg/24h.
Conclusions: The giant malignant paraganglioma located in liver is a very rare neuroendocrine tumor. The correct diagnosis and successfully surgical resection of tumor are important for those patients with paraganglioma. They must be followed up for a long time.