Recently experienced ten cases of insulinoma--preoperative diagnosis of localization and intraoperative simultaneous monitoring of glucose and insulin

We have experienced 10 cases of insulinoma during the last 10 years from 1977 to 1986. All cases had strong hypoglycemic symptoms such as disturbance of consciousness, and insulinoma still tended to be misdiagnosed as epilepsy. The diagnosis of insulinoma was easily available from serum IRI (immunoreactive insulin)/plasma glucose ratio in all of the ten cases. As preoperative procedures for the diagnosis of localization, arteriography, computed tomography and portal blood sampling were positive in 6 of 8, 4 of 6 and 2 of 2 patients, respectively. At operation, all insulinomas could be identified by digital palpation. We performed simple excision of the tumor in 6 patients and distal pancreatectomy in 4 patients. The tumors were solitary and benign in all patients, ranging in size from 1.0 cm to 4.5 cm. Three cases were presented as case reports. In these cases, portal blood sampling and/or intraoperative monitoring of plasma glucose and serum IRI were performed. Portal blood sampling was effective even for a case which was negative in image diagnostic procedures. Furthermore, simultaneous monitoring of plasma glucose and serum IRI by quick radioimmunoassay seemed to be a good guide to the completeness of resection of insulin producing tumors.     

Role of intraoperative ultrasonography in the surgical management of insulinomas

The findings in 35 surgically treated patients with insulinoma and 43 tumors of these patients were analyzed to confirm the efficacy of diagnostic modalities and surgical interventions. The rate of accurate preoperative tumor localization was 72% by angiography, 53% by computed tomographic scan, 55% by ultrasonography, and 83% by percutaneous transhepatic portal vein sampling. Extensive operative exposure and palpation detected 81% of the tumors and intraoperative ultrasonography demonstrated 96% of the tumors. Intraoperative ultrasonography was significantly better than any other diagnostic procedure and was able to demonstrate the anatomical relationship of the insulinoma to the essential structures of the pancreas. Intraoperative ultrasonography also helped determine the safest route for enucleating the insulinomas. Five patients (14%) in our series had metastatic diseases; 2 of these patients with metastases beyond the lymph nodes died due to the growth of tumors. The other 33 patients were free of insulinoma syndrome after the removal of the insulinomas. Streptozotocin was used in 1 patient with recurrent malignant insulinoma, with encouraging results.     

Insulinoma: Selective arterial calcium injection performed to confirm localization and complete resection

A case of insulinoma is reported in a patient in whom selective arterial calcium injection (SACI) tests were performed both to confirm tumor localization before surgery and to confirm complete tumor removal during surgery. An 18-year-old woman with hypoglycemic episodes was diagnosed with an insulinoma in the pancreatic body demonstrated by celiac arteriography. In a preoperative SACI test, calcium was injected into the splenic artery (SpA), gastroduodenal artery (GDA), and superior mesenteric artery (SMA). Serum immunoreactive insulin (IRI) and proinsulin levels were measured in hepatic venous samples. IRI was markedly increased after the injection of calcium into the GDA and SMA, while there was no response in IRI levels when calcium was injected into the SpA. Therefore, no occult insulinoma was revealed in the distal area fed by the SpA, although the presence of insulinoma was uncertain in the proximal pancreas. In the intraoperative SACI test, calcium was injected into the celiac artery. Insulin (determined by enzyme immunoassay) and proinsulin levels were measured in portal venous samples before and after resection of the tumor. After resection, these levels decreased in response to the calcium stimuli, confirming complete removal of the insulinoma. The SACI test was helpful to localize the insulinoma and was useful to confirm the complete removal of the tumor.     

Rapid insulin assay for intraoperative confirmation of complete resection of insulinomas

BACKGROUND: Solitary insulinomas are usually the cause of organic hypoglycemia, whereas 13% to 24% of patients with hyperinsulinemia have multiple tumors or nesidioblastosis. Intraoperative glucose levels confirming complete excision have variable accuracy. Intraoperative insulin levels have been shown to predict operative outcome. The purpose of this study was to establish criteria for predicting operative success by using a new, rapid insulin assay as an intraoperative adjunct. METHODS: Eight consecutive patients with organic hypoglycemia underwent pancreatic exploration. With an 8-minute immunochemiluminescent insulin assay, peripheral blood levels were obtained preoperatively, during resection, and at 5-minute intervals after surgical excisions. Operative findings and outcome were compared with intraoperative insulin/glucose ratios (I/G), glucose, and insulin levels. RESULTS: By using the return of insulin levels to normal range and I/G ratios < or = 0.4 15 minutes after tumor(s) resection as criteria to predict operative success, 6 patients had their outcomes correctly predicted (5 true-positive and 1 true-negative). One patient with nesidioblastosis had a false-negative result. One could not be evaluated because of diazoxide medication. These criteria predicted postoperative absence of hypoglycemia with specificity of 100% and accuracy of 89%. CONCLUSIONS: These 8-minute insulin assay and criteria can be a useful adjunct for intraoperative assurance of complete insulinoma resection and prediction of postoperative outcome.     

Rebound hyperglycemia and peroperative normalization of insulinemia. Complete excision of insulinoma?]

Clinical usefulness of the hyperglycemic rebound and the normalization of plasma insulin level as intraoperative markers of complete removal of insulinoma was assessed. Surgical removal was curative (no clinical or biological recurrence) in six patients harboring a single adenoma (mean follow-up = 32.2 months). In these patients plasma glucose increased an average of 32 mg/dl 30 minutes after resection, 68 mg/dl after 60 minutes, and 91 mg/dl after 90 minutes. Sensitivity of hyperglycemic rebound (defined as a plasma glucose increment of at least 30 mg/dl after tumor removal) as a marker of complete resection of the insulinoma was 40% at 30 min and 83% at 60 minutes after resection. Preresectional values of plasma immunoreactive insulin were elevated in 3 out of 4 patients with adenoma. All postresectional values were within normal ranges. Two patients operated on because of malignant insulinoma, underwent partial tumor resection; hyperglycemic rebound was also present, and high preresectional insulin values became normal 30 minutes after partial tumor removal. We conclude that information provided by intraoperative monitoring of both plasma glucose and insulin cannot be used as the only markers of complete resection of all insulinomas. Only long term clinical and biological follow-up can guarantee the complete resection of an insulinoma.     

Localization and surgical treatment of occult insulinomas.

Management of patients with biochemical evidence of insulinoma and negative preoperative imaging studies (occult) tumors is controversial, varying from primarily medical management to aggressive, blind nearly total pancreatectomy to extirpate the tumor. Since 1982, 12 consecutive patients with occult insulinoma underwent preoperative portal venous sampling (PVS) for insulin followed by surgical exploration with intraoperative ultrasound (IOUS). Eleven of twelve patients (92%) had insulinoma removed and were cured. Portal venous sampling correctly predicted the location of the insulinoma in 9 patients (75%) and that no tumor would be found in another patient. A fourfold insulin gradient in the pancreatic tail of one patient correctly predicted that a distal pancreatectomy would remove the insulinoma despite the fact that neither palpation nor IOUS identified any tumor. Intraoperative ultrasound was the single best method to identify occult tumors because it correctly identified 10 of 11 insulinomas that were found, including five pancreatic head tumors that were not palpable. Palpation identified five insulinomas. Of the 10 tumors that were identified during operation by palpation or ultrasound, IOUS identified significantly more (100% versus 50%, p = 0.03) and guided the successful enucleation of each. The results support the strategy of preoperative PVS and operation with IOUS to localize and remove insulinoma in patients with occult tumors. Most tumors (75%) will be correctly localized to a specific pancreatic region by preoperative PVS and identified by IOUS (83%), allowing simple enucleation and biochemical correction of hypoglycemia. Morbid blind pancreatic resections are no longer indicated and long-term medical management of hypoglycemia should be reserved for the occasional patient (8%) who fails preoperative PVS and operation guided by IOUS.     

Anesthetic management of two patients with insulinoma using propofol--in association with rapid radioimmunoassay for insulin

We experienced anesthetic management of two patients with insulinoma in whom frequent hypoglycemic episodes with blood glucose levels of 39-42 mg.dl-1 had been observed. Each patient received epidural analgesia with a catheter inserted at the T 9/10 intervertebral space. Anesthesia was induced with propofol 80-100 mg and fentanyl 200 micrograms. Tracheal intubation was facilitated with vecuronium 6 mg. Anesthesia was maintained with continuous infusion of propofol and epidural anesthesia. Rapid measurements of immunoreactive insulin (IRI) were useful for localization of insulinoma during surgery. Perioperative plasma glucose levels could be maintained within normal ranges by continuous infusion of glucose. Rebound hyperglycemic episodes were not observed, and IRI was reduced after removal of the insulinoma. General anesthesia using propofol and epidural block is a useful choice for the anesthetic management of patients undergoing an operation for removal of an insulinoma.     

Results of a prospective strategy to diagnose, localize, and resect insulinomas.

Since 1982, 25 consecutive patients with benign sporadic (non-multiple endocrine neoplasia type I) insulinomas have been studied. Most were referred because either the tumor was not identified at the referring institution or the diagnosis was unclear. Each patient suffered severe neuroglycopenic symptoms for a median of 24 months before diagnosis of insulinoma, and 32% had hypoglycemic seizures. Eighteen patients (72%) had a confirmed weight gain. Each patient underwent a supervised fast until 72 hours or the onset of significant neuroglycopenic symptoms (median duration 16 hours), with serum levels of glucose (median 35 mg/dl; range 24 to 46 mg/dl), insulin (median 21 microU/ml; range 11 to 230 microU/ml), C-peptide (median 2.5 ng/ml; range 1.0 to 7.2 ng/ml), and proinsulin fraction (median 55%; range 14% to 86%) measured at the termination of the fast. Preoperative imaging with ultrasonography, computed tomography, magnetic resonance, and angiography visualized tumor in a minority of patients (26%, 17%, 25%, and 35%, respectively); in 48% of patients one or more imaging study results was positive. Selective portal venous sampling for insulin was the most informative localizing test (77% positive; no false-positive results). Tumor was resected for cure in 24 of 25 patients. Intraoperative ultrasonography identified nonpalpable tumor in seven patients and was crucial to the achievement of this high rate of surgical cure. We conclude that the diagnosis of insulinoma can be made by the results of a supervised fast, portal venous sampling is the most sensitive preoperative test for localizing insulinomas, and intraoperative ultrasonography is essential for intraoperative detection of insulinomas.     

功能性胰岛素瘤的诊治(附12例)

目的 探讨功能性胰岛素瘤的诊治特点,提高对该病的认识.方法 回顾性分析2000年至2009年吉林大学中日联谊医院收治的12例功能性胰岛素瘤临床资料.结果 12例术前空腹血糖值和胰岛素阳性率分别为92%和89%,IRI/G和C-肽的阳性率达100%.术前腹部超声、CT和MRI定位诊断准确率分别是75%、36%和0%,而术中扪诊结合术中超声的定位准确率达100%.术中血糖监测,10例在肿瘤切除后1 h内血糖上升1倍以上,2例1.5 h后上升1倍以上.随访7例,均未再出现低血糖症状.3例胰瘘.结论 对疑有功能性胰岛素瘤的病例,除检测血糖、胰岛素外还应检测IRI/G、C-肽.术中扪诊及超声是肿瘤定位的有效手段.监测肿瘤切除后血糖变化,结合术中快速病理可判定肿瘤是否完全切除.     

A prospective evaluation of laparoscopic exploration with intraoperative ultrasound as a technique for localizing sporadic insulinomas

BACKGROUND: Preoperative imaging studies localize insulinomas in less than 50% of patients. Arteriography with calcium stimulation and venous sampling (ASVS) regionalizes greater than 90% of insulinomas but requires specialized expertise and an invasive procedure. This prospective study evaluated laparoscopic exploration with IOUS compared with the other localization procedures in patients with a sporadic insulinoma. METHODS: Between March 2001 and October 2004, 14 patients (7 women and 7 men; mean age, 53) with an insulinoma were enrolled in an IRB-approved protocol. Computed tomography, magnetic resonance imaging, ultrasound scan, and arteriography with calcium stimulation and venous sampling were performed preoperatively. A surgeon, blinded to the results of the localizing studies, performed a laparoscopic exploration with intraoperative ultrasound (IOUS). At the completion of the exploration, the success of laparoscopy for localization was scored, and the tumor was resected. RESULTS: Twelve of 14 tumors were localized successfully before laparoscopy (noninvasive, 7 of 14; invasive, 11 of 14). Laparoscopic IOUS localized successfully 12 of 14 tumors. All lesions were resected, and all patients were cured (median follow-up, 36 months). CONCLUSION: Laparoscopic IOUS identified 86% of tumors. The authors consider laparoscopic IOUS to be equivalent to ASVS in localizing insulinomas. Further study is therefore warranted to determine the role of laparoscopy with IOUS in the localization and treatment algorithm for patients with sporadic insulinoma.     

The management of insulinoma

BACKGROUND: Insulinomas are rare tumours. Their clinical presentation, localization techniques and operative management were reviewed. METHODS: An electronic search of the Medline, Embase and Cochrane databases was undertaken for articles published between January 1966 and June 2005 on the history, presentation, clinical evaluation, use of imaging techniques for tumour localization and operative management of insulinoma. RESULTS AND CONCLUSION: Most insulinomas are intrapancreatic, benign and solitary. Biochemical diagnosis is obtained during a supervised 72-h fast. Non-invasive preoperative imaging techniques to localize lesions continue to evolve. Intraoperative ultrasonography can be combined with other preoperative imaging modalities to improve tumour detection. Surgical resection is the treatment of choice. In the absence of preoperative localization and intraoperative detection of an insulinoma, blind pancreatic resection is not recommended.     

功能性胰岛素瘤的诊治(附12例)

目的 探讨功能性胰岛素瘤的诊治特点,提高对该病的认识.方法 回顾性分析2000年至2009年吉林大学中日联谊医院收治的12例功能性胰岛素瘤临床资料.结果 12例术前空腹血糖值和胰岛素阳性率分别为92%和89%,IRI/G和C-肽的阳性率达100%.术前腹部超声、CT和MRI定位诊断准确率分别是75%、36%和0%,而术中扪诊结合术中超声的定位准确率达100%.术中血糖监测,10例在肿瘤切除后1 h内血糖上升1倍以上,2例1.5 h后上升1倍以上.随访7例,均未再出现低血糖症状.3例胰瘘.结论 对疑有功能性胰岛素瘤的病例,除检测血糖、胰岛素外还应检测IRI/G、C-肽.术中扪诊及超声是肿瘤定位的有效手段.监测肿瘤切除后血糖变化,结合术中快速病理可判定肿瘤是否完全切除.     

Sevoflurane anesthesia for a patient with insulinoma]

A 56-y-o female had recurrent bouts of unconsciousness and convulsions. Her blood glucose level was often below 40 mg.dl-1. Blood chemistry, echography and angiography revealed an insulinoma of 14 x 12 mm in size. Under sevoflurane anesthesia, excision of the tumor was scheduled. The preanesthetic glucose level was 38 mg.dl-1. Under fluid therapy, with 5% glucose in acetate Ringer solution, no hypoglycemic episode occurred during and after the operation. The arterial IRI level was elevated as the blood glucose level increased before the extirpation of the tumor, but it decreased to the normal level 30 minutes after the tumor removal. The IRI level of the portal vein also decreased from 81.7 microU.ml-1 to 19.0 microU.ml-1 after the removal. The perioperative course was uneventful under sevoflurane anesthesia and the result substantiates the report by Murakawa et al, who contend that sevoflurane suppresses the spontaneous release of insulin. We believe that sevoflurane is an appropriate anesthetic agent for a patient with an insulinoma.     

Laparoscopic detection and resection of insulinomas

BACKGROUND: Laparoscopic ultrasonography as a diagnostic tool for the localization of islet cell tumors has been described before, but few reports on laparoscopic resection of insulinomas exist. We retrospectively reviewed the results of our experience with laparoscopic detection and the resection of insulinomas to determine its feasibility. METHODS: Between February 1996 and February 1999, 10 patients underwent operation for organic hyperinsulinism at our institution. Patient and clinical characteristics were studied retrospectively. Laparoscopic ultrasonography was performed to localize the insulinoma and then laparoscopic resection was performed. RESULTS: Eight women and 2 men underwent operation for hyperinsulinism. In 6 patients the insulinoma could be resected laparoscopically, either by enucleation (5 patients) or by resection of the pancreatic tail (1 patient). Four procedures were converted to laparotomy for the proximate location of the insulinoma to the portal vein or pancreatic duct (3 procedures) and failure to identify the insulinoma (1 procedure). The overall success rate of preoperative localization of an insulinoma with the use of various imaging techniques was 60% (6/10 patients). Laparoscopic ultrasonography could identify an insulinoma in 90% of the patients (9/10 patients). The median hospital stay was 7 days. CONCLUSIONS: Laparoscopic ultrasonography followed by laparoscopic removal of the insulinoma in patients with clinically manifested hyperinsulinism is a feasible and safe technique with low morbidity and fast postoperative recovery. Preoperative localization studies appear of limited value.     

Intraoperative ultrasound of the pancreas in hyperinsulinism

In four cases of hyperinsulinism proven clinically and by blood chemistry the value of intraoperative sonography of the pancreas is emphasized. An insulinoma could be localized preoperatively in two patients. In one of these two cases intraoperative sonography detected additional insulinomas. In the remaining two patients the negative preoperative examinations and surgical palpation was confirmed by using this method: diffuse islet cell hyperplasia was the final diagnosis in both cases.     

Localization and surgical treatment of the pancreatic insulinomas

OBJECTIVES: Insulinomas are rare tumours that originate from the islet cells of the pancreas. The aims of this study were to gain an understanding of the clinical features of insulinomas and to establish the diagnostic and therapeutic strategies. METHODS: A review was carried out in 20 patients with insulinoma surgically treated in our institution over the last 10 years. Presenting symptoms, biochemical studies, preoperative and intraoperative localization studies, operative management and complications were analysed. RESULTS: The male-to-female ratio was 8:12, with a mean age of 46.4 years. Each patient suffered from significant neuroglycopenic symptoms, usually manifested by dizziness, sweating, headache and confusion. The preoperative median serum levels of glucose, insulin and C-peptide at the termination of the fast were 37.5 mg/dL, 23.5 microU/mL, 5.6 ng/mL, respectively. Preoperative tumour localization was achieved by means of ultrasonography (US), computed tomography, selective angiography or intra-arterial calcium injection with hepatic venous sampling, and sensitivities of these examinations were 81.8, 73.7, 94.1 and 100%, respectively. Intraoperative localization was carried out by a combination of manual palpation and intraoperative US with retrospective sensitivities of 80 and 100%, respectively. Enucleation was carried out in 16 patients and distal pancreatectomy in 4. The mortality and morbidity rates were 0 and 10%, respectively. One patient developed late diabetes mellitus type 1 after distal pancreatectomy. CONCLUSIONS: We conclude that the diagnosis of insulinoma can be made on the basis of the results of a supervised fast, careful palpation with intraoperative US is essential for intraoperative detection of insulinomas and surgical resection is the best choice for treatment of benign insulinomas.     

Is preoperative localization of insulinomas justified?

STUDY AIM: To appreciate the impact of preoperative localization in surgical treatment of insulinomas. PATIENTS AND METHOD: From 1986 to 2001, 29 patients were surgically treated for suspected insulinoma. Preoperative imaging assessment was performed in 26 patients: ultrasonography (n = 21), computed tomography (n = 23), endoscopic ultrasonography (n = 13), intraoperative ultrasonography (n = 22) (2 of them under laparoscopic approach). RESULTS: The sensibility of the localization procedures was as follows: ultrasonography = 9.6%, computed tomography = 39%, endoscopic ultrasonography = 92.3%, surgical exploration 79.3%, intraoperative ultrasonography 86.3%. The sensibility of intraoperative palpation associated which intraoperative ultrasonography was 100%. Surgical procedures included: 11 enucleations, 10 segmental resections of the tail, 1 left pancreatectomy, 3 median pancreatectomies, 4 subtotal pancreatectomies. There was no postoperative mortality and postoperative morbidity rate was 17%, including 4 pancreatic leakages. Histological examination found solitary tumor in 22 patients (1 of them was a malignant tumor), multiple tumors (MEN 1) in 4 patients and factitious hypoglycemia in 3 patients. All the insulinomas were resected. CONCLUSION: Intraoperative evaluation of the pancreas with intraoperative ultrasonography was associated which a right localization in 100% of insulinomas. The place for preoperative imaging seems to be limited. A laparoscopic approach in sporadic insulinomas could modify this attitude.     

Preoperative localization of insulinomas is not necessary.

BACKGROUND: Insulinomas are infrequent but are important to recognize and surgically remove. Several diagnostic tests have been used to increase the chances of operative success. The value of preoperative testing for insulinomas is the subject of this review. STUDY DESIGN: All patients treated at the Cleveland Clinic for insulinoma between 1985 and 1995 were retrospectively reviewed. All patients had biochemical evidence of primary hyperinsulinemia. RESULTS: There were 21 patients, 10 men and 11 women, with a median age of 58 years. Eighteen patients (85%) had a single insulinoma, two patients (10%) had multiple insulinomas, and one patient (5%) had nesidioblastosis. In addition, two patients (10%) had malignant insulinoma. A total of 13 patients (62%) had successful preoperative localization of their tumors, and all of these were found during exploration either by the surgeon (12 patients) or by intraoperative ultrasonography (1 patient). The remaining eight patients (38%) did not have their lesion localized by preoperative tests. In seven patients these tumors were found at operation, three by the surgeon and four by intraoperative ultrasonography. One patient failed preoperative and intraoperative localization and was later diagnosed with nesidioblastosis. Enucleation was performed in 13 patients and distal pancreatectomy in 7; the patient with nesidioblastosis had a negative laparotomy and a subsequent distal pancreatectomy. The mortality and morbidity rates were 0% and 14%, respectively. Only two patients, including the patient with nesidioblastosis, remained symptomatic after operation. CONCLUSIONS: The diagnosis of an insulinoma does not require extensive localization studies before operation. The combination of surgical exploration and intraoperative ultrasonography identified more than 90% of insulinomas. When technically feasible, enudeation is curative and can be accomplished with low morbidity.     

Value of intra-arterial calcium stimulated venous sampling for regionalization of pancreatic insulinomas

BACKGROUND: Intra-arterial calcium stimulation with hepatic venous sampling (ASVS) for insulin gradients has been reported to be the most sensitive preoperative localizing technique for insulinomas. We reviewed our experience with ASVS to localize and guide the treatment of insulinomas over the past decade. METHODS: Eighteen patients who underwent ASVS before surgical exploration for insulinoma were studied. The accuracy of ASVS was compared with intraoperative findings and other localizing studies. RESULTS: There were no complications arising from the procedures. A more than 2-fold step-up in insulin level 30 to 60 seconds after injection to at least 1 feeding artery was observed in 16 patients. Fourteen of the 16 solitary tumors (87.5%) were correctly located; 100% (6/6 tumors) at the head and 80% (8/10 tumors) at the body/tail. The overall accuracy of this test was 89%, compared with 11%, 33%, 38%, and 63% of ultrasonography, computed tomography, magnetic resonance imaging, and endoscopic ultrasonography, respectively. Six enucleations and 10 distal resections were performed, which included 2 laparoscopic procedures. The combination of intraoperative ultrasonography with preoperative ASVS identified all tumors. CONCLUSIONS: ASVS is the most accurate preoperative localization tool for the localization of insulinomas and, in combination with intraoperative ultrasonography, can enhance surgical success.     

胰岛素瘤的诊断和治疗：附120 例报告

目的:探讨胰岛素瘤的诊断与治疗方法。方法:回顾性分析40 年间收治的120 例胰岛素瘤患者的临床资料。结果:全组患者均有Whipple三联症的临床表现，血糖均<2.75mmol/L；75 例空腹血清胰岛素>25μU/mL，平均(65 ±6.0)μU/mL。术前B 超检查60 例，2 例发现肿瘤；CT 检查50 例，10 例发现肿瘤；术中B 超检查18 例，16 例与术中探查相符，1 例发现了未能扪及的肿瘤。良性肿瘤112例，恶性肿瘤4例，胰岛细胞增生症4例。行单纯肿瘤摘除70 例，行包括肿瘤在内的胰体尾脾切除44 例，单纯胰体尾切除4 例，活检2 例。112 例良性胰岛素瘤术后111 例低血糖症状立即消失，1 例术后仍有低血糖症状发作，通过再次手术时发现钩突部肿瘤，切除后治愈。继发胰瘘20 例，均为肿瘤摘除者，其中14 例经引流自愈，5例经手术治疗痊愈，1 例因腹腔感染死亡。结论:胰岛素瘤术前定位不易，术中探查及术中B 超是发现肿瘤的主要手段；对良性者应力争行肿瘤摘除术，对肿瘤位于胰体尾较大且深或多发肿瘤者应行胰体尾切除术。