Case report: A Re-operation Case of Asymptomatic Left Giant Pheochromocytoma and Literature Review

Abstract Introduction: Pheochromocytoma (PCC) is a rare tumor which derives from adrenal medulla, when maximum diameter of pheochromocytoma is greater than 10CM, it is divided into Giant pheochromocytoma(GPCC), which is extremely rare and usually asymptomatic.Clinically, a huge and asymptomatic adrenal pheochromocytoma was usually misdiagnosed as other types of tumors, which result in notable increase of complication rates and death rates.Case presentation:In this case report, we described a clinically asymptomatic GPCC patient. Diagnosis:According to computed tomography (CT) scan, nuclear magnetic resonance(MR) scan, the patient is initially diagnosed as liposarcoma.After laparotomy, biochemical detection of catecholamine (CA) intermediate metabolites methoxyepinephrine (MN) and methoxy norepinephrine (NMN) and the pathological examination , diagnosis of GPCC was obtained. Intervention：The laparotomy was suspended and a diagnosis of pheochromocytoma was confirmed, because of unstable blood pressure and hypertension during separating and moving the mass during surgery. After consultation of multi-disciplinary team, adequate preoperative preparation was conducted according to the procedure of PCC surgical preparation. By the end of the regular phenoxybenzamine and intravenous fluids treatment for three weeks, the blood pressure of the patient was kept at an acceptable average. Therefore, the patient underwent the operationagain for radical resection. Outcome: After the operation, CA was basically normal in rechecking process, and the tumor was successfully removed. Pathological diagnosis of the mass after operation: Immunohistochemical resulted conformed to (epigastrium) pheochromocytoma. Immunohistochemistry: CgA(+), Inhibin-α(-), ki-67(<1%+), Syn(+). Pheochromocytoma had the definite pathological diagnosis. Conclusion: GPCC has the high diagnostic identification difficulty, it should be combined with imaging examination and biochemical measurement to identify. Before operation, the detailed imageological examination provides important reference for excision and surgical planning. Individualized and multi-disciplinary cooperation of management strategy in perioperative period should be recommended. Patients should conduct long-term follow-up.