2.1. Disease history and auxiliary examination：
The patient was a 30-year-old man with an abdominal mass more than 4 months，examined by abdominal B-ultrasound in outpatient pharmacy of our hospital and suggested an occupying lesion in abdomen. Then retroperitoneal tumors was diagnosed and admitted in the hospital. The patient had no abdominal distension, abdominal pain, constipation, diarrhea, dizziness, headache, palpitation, shortness of breath, back pain, or progressive emaciation, his previous medical history is without any paroxysm hypertension, diabetes, surgery or trauma. The patient's mother and father are healthy. No family history of diseases or tumors. Physical examinations: Temperature 37.2℃, Heart rate 63 times/min, Respiration18 times/min，Blood pressure 120/80mmHg. A crucial finding on physical examination is obvious protrusion mass in upper left abdomen，approximately 15cm×12cm in size. The abdomen is supple without epigastric varicose veins or tenderness, rebound tenderness. Some additional tests were performed after admission, such as "three great regular tests", second liver two half-and-half detect, three indexes before blood transfusion, four coagulation tests, 36 biochemical indexes, tumor markers , Chest radiographs, and showed no abnormalities. Electrocardiograms: obvious sinus bradycardia complicated witharrhythmia, junctional escapebeat, 44 times/min. Ambulatory electrocardiogram: 1. sinus rhythm, longest R-R< 2.0s; 2. occasional atrial premature; 3. ST-T change. Important image detections, such as upperand lower abdominal CT（plain and enhanced）+CTA+CTV (Fig.1) showed: 1. left upper abdominal and retroperitoneal huge mass was considered as malignant lesion, doubtful of myxoid liposarcoma. 2. considered as intrahepatic scattered small cyst. 3. CTA showed compression and displacement of splenic artery and left renal artery, blood vessels of superior mesenteric artery and small branches of splenic artery appeared on the substantial part of tumor edge. 4. CTV showed compression and displacement of splenic vein, but without filling defect. Superior abdominal MR suggested a irregular mass in left upper-middle abdomen, which is about 18cm×18cm×15cm in size, with Heterogeneous signal (Fig.2). Multiplenecrosis and cystic lesions were detected in the mass. The stomach was compressed leading to displacement to the front and the right, the spleen was compressed to the left lateral, and the spleen, pancreas and the left kidney were compressed downward. Lesions showed significant but heterogenous enhancement and could not be separated from the pancreas and spleen，but showed clear boundaries with other surrounding structures. The diagnosis of upper left retroperitoneal malignant mesenchymoma was made by the radiography, possibly liposarcoma, leading to displacement of the spleen and the left kidney. Based on this information and the patient's medical history, radical resection is the first choice.
2.2. First operation.
Temporary pacemaker was used to treat decreased heart rate of the patient after hospitalized. Subsequently, the patient was subjected to laparotomy and a diagnosis of pheochromocytoma was evacuated on October 10, 2017. Unstable blood pressure and hypertension (up to 330/160mmHg) during separating and moving the mass leaded to suspension of surgery and is admitted to the intensive care unit.
Postoperative auxiliary examination: adrenocorticotrophic hormone 10.56 pg/mL. Determination of plasma cortisol: cortisol15.11ug/dL. Determination of Angiotensin 1+Angiotensin 2+aldosterone：aldosterone77.17pg/ml，plasma renin activity 6.76ng/mL/hr，angiotensin I 8.16ng/mL，angiotensin I1.40ng/mL，angiotensin II 58.92pg/mL (October 19, 2017). Determination of amylase (Rate method) : amylase 320 U／L (October 20, 2017). Determination of urinary potassium (24 hours): potassium56.30mmol/24h (October 21, 2017).
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 (100-120mmHg/60-80mmHg), heart rate60-90 beats /min . Erratic blood pressure only appeared before sleep (Systolic pressure100-150mmHg). Therefore, the patient underwent the operation again on November 15, 2017.
2.3 The second surge
Abdominal exploration showed slight adhesion, and large cystic solid mass in the left abdomen, about the size of 18cmⅹ21cmⅹ19cm, moderate hardness, close adhesion with greater curvature and jejunum, with invasion of pancreatic tail, splenic artery, splenic vein. No obvious metastasis was found in liver, kidney, hepatic hilar region or mesenteric roots. Slight fluctuation of blood pressure occurred during abdominal exploration. Intraoperative diagnosis is left adrenal pheochromocytoma and resection of left giant adrenal pheochromocytoma + splenectomy + partial resection of the pancreas tail+ enterolysis were performed in surgery: released the adhesion intestinal canal, incised the gastrocolic ligament, fully exposed the pancreas，and separated the mass over the pancreas. Then the splenic artery and splenic vein were ligatured, a part of pancreatic tails was removed. A drag hook was used to pull the abdominal wall towards the left side, while the spleen was dragged towards right side, showing external lienorenal ligament. An ultrasound knife was used for cutoff. It was separated towards the fundus of stomach from the greater curvature to cut off gastrosplenic ligament. Also, short gastric vessel was ligated one by one, dissociating the upper half and inside margin of left kidney, revealing the adrenal gland, carefully separating from the adrenal gland and ambient adipose tissues, and completely dissociating and cutting off the entire tumor. In the dissociated process, blood pressure was fluctuated at 60/40mmHg-230/130mmHg. Heart rate was fluctuated at times/second. Body of pancreas and spleen were combined with the left adrenal gland to cut off and move out of the abdominal cavity. After the posterior peritoneum wound surface fully stopped bleeding, a drainage tube was placed at the spleen fossa. Instruments and gauze were counted without errors. Abdomen was closed layer by layer. The operation process was successful and anesthesia was satisfactory. Amount of bleeding in operation was about 500mL. After the operation, the patient returned to the ward. A specimen was cut off for conventional pathological examination.(Figure 3)
2.4 Postoperative conditions and pathological results.
After the operation, the patient was sent to ICU for nursing. In the second day after operation, the patient had a fever. After the patient accepted anti-infective therapy, vital signs gradually tended to be smooth. After the third week of operation, CA was basically normal in rechecking process. Considering that the tumor was cut off successfully, the patient was allowed to discharge from the hospital. Pathological diagnosis of the mass after operation: 1. Immunohistochemical resulted conformed to (epigastrium) pheochromocytoma, showing invasion of suspicious diolame; 2. Spleen and pancreatic tissue showed chronic inflammation and atrophy changes, showing no tumor invasion; there was no tumor in surrounding adipose tissues. Immunohistochemistry: CgA(+), Inhibin-α(-), ki-67(<1%+), Syn(+). Pheochromocytoma had the definite pathological diagnosis. (Figure 4). It hasn’t relapsed after 8-month follow-up.