Therapeutic experience of 65 cases with organic hyperinsulinism

Diffuse, Adult-Onset Nesidioblastosis/Non-Insulinoma Pancreatogenous Hypoglycemia Syndrome (NIPHS): Review of the Literature of a Rare Cause of Hyperinsulinemic Hypoglycemia

Differential diagnosis of hypoglycemia in the non-diabetic adult patient is complex and comprises various diseases, including endogenous hyperinsulinism caused by functional β-cell disorders. The latter is also designated as nesidioblastosis or non-insulinoma pancreatogenous hypoglycemia syndrome (NIPHS). Clinically, this rare disease presents with unspecific adrenergic and neuroglycopenic symptoms and is, therefore, often overlooked. A combination of careful clinical assessment, oral glucose tolerance testing, 72 h fasting, sectional and functional imaging, and invasive insulin measurements can lead to the correct diagnosis. Due to a lack of a pathophysiological understanding of the condition, conservative treatment options are limited and mostly ineffective. Therefore, nearly all patients currently undergo surgical resection of parts or the entire pancreas. Consequently, apart from faster diagnosis, more elaborate and less invasive treatment options are needed to relieve the patients from the dangerous and devastating symptoms. Based on a case of a 23-year-old man presenting with this disease in our department, we performed an extensive review of the medical literature dealing with this condition and herein presented a comprehensive discussion of this interesting disease, including all aspects from epidemiology to therapy.

Multiple Endocrine Neoplasia Type 1 (MEN1): An Update and the Significance of Early Genetic and Clinical Diagnosis

Multiple endocrine neoplasia type 1 (MEN1) is a rare hereditary tumor syndrome inherited in an autosomal dominant manner and characterized by a predisposition to a multitude of endocrine neoplasms primarily of parathyroid, enteropancreatic, and anterior pituitary origin, as well as nonendocrine neoplasms. Other endocrine tumors in MEN1 include foregut carcinoid tumors, adrenocortical tumors, and rarely pheochromocytoma. Nonendocrine manifestations include meningiomas and ependymomas, lipomas, angiofibromas, collagenomas, and leiomyomas. MEN1 is caused by inactivating mutations of the tumor suppressor gene MEN1 which encodes the protein menin. This syndrome can affect all age groups, with 17% of patients developing MEN1-associated tumors before 21 years of age. Despite advances in the diagnosis and treatment of MEN1-associated tumors, patients with MEN1 continue to have decreased life expectancy primarily due to malignant neuroendocrine tumors. The most recent clinical practice guidelines for MEN1, published in 2012, highlight the need for early genetic and clinical diagnosis of MEN1 and recommend an intensive surveillance approach for both patients with this syndrome and asymptomatic carriers starting at the age of 5 years with the goal of timely detection and management of MEN1-associated neoplasms and ultimately decreased disease-specific morbidity and mortality. Unfortunately, there is no clear genotype-phenotype correlation and individual mutation-dependent surveillance is not possible currently.

The future: surgical advances in MEN1 therapeutic approaches and management strategies

Multiple endocrine neoplasia type 1 (MEN1) is a hereditary autosomal dominant disorder associated with numerous neuroendocrine tumors (NETs). Recent advances in the management of MEN1 have led to a decrease in mortality due to excess hormones; however, they have also led to an increase in mortality from malignancy, particularly NETs. The main challenges are to localize these tumors, to select those that need therapy because of the risk of aggressive behavior and to select the appropriate therapy associated with minimal morbidity. This must be applied to a hereditary disease with a high risk of recurrence. The overall aim of management in MEN1 is to ensure that the patient remains disease- and symptom-free for as long as possible and maintains a good quality of life. Herein, we review the changes that occurred in the last 20 years in the surgical management of MEN1-associated functional and non-functional pancreatico-duodenal NETs and thymic and bronchial NETs.

Long-term results of the surgical management of insulinoma patients with MEN1: a Groupe d'étude des Tumeurs Endocrines (GTE) retrospective study

OBJECTIVE

Management of insulinomas in the context of MEN1 remains poorly studied. The aim of this study was to evaluate long-term results of various surgical approaches in a large cohort of insulinoma-MEN1 patients.

DESIGN AND METHODS

Consecutive insulinoma-MEN1 patients operated on for a nonmetastatic insulinoma between 1957 and 2010 were retrospectively selected from the MEN1 database of the French Endocrine Tumor Group. The type of surgery was categorized as distal pancreatectomy (DP), total pancreatectomy/cephalic duodenopancreatectomy (TP/CDP), or enucleation (E). Primary endpoint was time until recurrence of hypoglycemia after initial surgery. Secondary endpoints were post-operative complications.

RESULTS

The study included 73 patients (median age=28 years). Surgical procedures were DP (n=46), TP/CDP (n=9), or E (n=18). After a median post-operative follow-up of 9.0 years (inter-quartile range (IQR): 2.5-16.5 years), 60/73 patients (82.2%) remained hypoglycemia free. E and TP/CDP were associated with a higher risk of recurrent hypoglycemia episodes (unadjusted hazard ratio: 6.18 ((95% CI: 1.54-24.8); P=0.010) for E vs DP and 9.51 ((95% CI: 1.85-48.8); P=0.007) for TP/CDP vs DP. After adjustment for International Union against Cancer pTNM classification, enucleation remained significantly associated with a higher probability of recurrence. Long-term complications had occurred in 20 (43.5%) patients with DP, five (55.6%) with TP/CDP, but in none of the patients who have undergone E (P=0.002).

CONCLUSION

In the French Endocrine database, DP is associated with a lower risk for recurrent hypoglycemia episodes. Due to lower morbidity, E alone might be considered as an alternative.

Consensus Recommendations for the Diagnosis and Management of Pancreatic Neuroendocrine Tumors: Guidelines from a Canadian National Expert Group

Pancreatic neuroendocrine tumors (pNETs) are rare heterogeneous tumors that have been steadily increasing in both incidence and prevalence during the past few decades. Pancreatic NETs are categorized as functional (F) or nonfunctional (NF) based on their ability to secrete hormones that elicit clinically relevant symptoms. Specialized diagnostic tests are required for diagnosis. Treatment options are diverse and include surgical resection, intraarterial hepatic therapy, and peptide receptor radionuclide therapy (PRRT). Systemic therapy options include targeted agents as well as chemotherapy when indicated. Diagnosis and management should occur through a collaborative team of health care practitioners well-experienced in managing pNETs. Recent advances in pNET treatment options have led to the development of the Canadian consensus document described in this report. The discussion includes the epidemiology, classification, pathology, clinical presentation and prognosis, imaging and laboratory testing, medical and surgical management, and recommended treatment algorithms for pancreatic neuroendocrine cancers.

Outcome after laparoscopic enucleation for non-functional neuroendocrine pancreatic tumours

BACKGROUND

Non-functional endocrine pancreatic tumours (NPT) of more than 2 cm have an increased risk of malignancy. The aim of the present study was: (i) to define the guidelines for laparoscopic enucleation (LapEn) in patients with a non-functional NPT ≤3 cm in diameter; (ii) to evaluate pancreas-related complications; and (iii) to present the long-term outcome.

METHODS

Between April 1998 and September 2010, 30 consecutive patients underwent laparoscopic surgery for a non-functional NPT (median age 56.5 years, range 44-83). Only 13 patients with tumours ≤3 cm in size underwent LapEn. Local lymph node dissection to exclude lymph node involvement was performed in all patients.

RESULTS

The median tumour size, operative time and blood loss were 2.8 cm (range 2.8-3), 130 min (range 90-280) and 220 ml (range 120-300), respectively. A pancreatic fistula occurred in five patients: International Study Group of Pancreatic Fistula (ISGPF) A in two patients and ISGPF B in three patients. The median follow-up was 48 months (12-144). Three patients with well-differentiated carcinoma are free of disease 2, 3 and 4 years after LapEn and a regional lymphadenectomy. One patient, 5 years after a LapEn, presented with lymph node and liver metastases.

CONCLUSIONS

The present study confirms the technical feasibility and acceptable morbidity associated with LapEn. Intra-operative lymph node sampling and frozen-section examination should be performed at the time of LapEn; when a malignancy is confirmed, oncologically appropriate lymph node dissection should be performed.

Insulinomatosis: a multicentric insulinoma disease that frequently causes early recurrent hyperinsulinemic hypoglycemia

BACKGROUND

Multicentric insulinoma disease was characterized with regard to its histopathology, multiple endocrine neoplasia type 1 (MEN1) status, precursor lesions, and the risk of hyperinsulinemic hypoglycemia recurrence.

METHODS

Fourteen patients with multicentric insulinoma disease were compared with 267 patients with sporadic and familial insulinomas. The tumors were classified according to the World Health Organization (WHO) criteria. The MEN1 status was defined clinically and by germline mutation analysis. Detection of the MEN1 gene locus was performed using fluorescence in situ hybridization. The surgical interventions and the duration of disease-free survival were recorded.

RESULTS

Fourteen patients (5%) without evidence of MEN1 showed 53 macrotumors and 285 microtumors expressing exclusively insulin. In addition, they had small proliferative insulin-expressing monohormonal endocrine cell clusters (IMECCs). No allelic loss of the MEN1 locus was detected in 64 tumors. All but one patient had benign disease. Recurrent hypoglycemia occurred in 6/14 patients (11 recurrences; mean time to relapse 8.4 y). Thirteen patients with MEN1 (4.6%) showed 41 insulinomas and 133 tumors expressing islet hormones other than insulin. IMECCs were not detected. Allelic loss of the MEN1 locus was found in 17/19 insulinomas. Recurrent hypoglycemia occurred in 4/13 patients (4 recurrences; mean time to relapse 14.5 y). Solitary insulinomas were found in 254/281 patients (90.4%). IMECCs were absent. There was no recurrent hypoglycemia in 84 patients with benign insulinomas.

CONCLUSIONS

Insulinomatosis is characterized by the synchronous and metachronous occurrence of insulinomas, multiple insulinoma precursor lesions, and rare development of metastases, but common recurrent hypoglycemia. This disease differs from solitary sporadic and MEN1-associated insulinomas.

Is laparoscopic resection adequate in patients with neuroendocrine pancreatic tumors?

Since the first reports with laparoscopic resection of islet cell tumors in 1996, the experience worldwide is still limited, with only short-term outcomes available. Some have suggested that a malignant tumor is a contraindication to laparoscopic resection. Aim The aim of this study was to evaluate the feasibility, safety, and long-term outcome of the laparoscopic approach in patients with functioning, nonfunctioning, or overt malignant pancreatic neuroendocrine tumor (PNT). To our knowledge this is the largest single-institution series on this subject to date. Patients and methods A total of 49 consecutive patients (43 women, 6 men; mean age 58 years, range 22-83 years) underwent laparoscopic pancreatic surgery (LPS) from April 1998 to June 2007. Preoperative localization was done by computed tomography, magnetic resonance imaging, endoscopic ultrasonography, and Octreoscan imaging. Other than 9 PNTs localized in the head of the pancreas, all tumors were located in the left pancreas. Malignancy was diagnosed based on the presence of lymph nodes or liver metastasis. There were 33 patients with functioning tumors: 4 with gastrinomas (mean size 1.2 cm), 1 with a glucagonoma (4 cm), 3 with vipomas (3.2 cm), 2 with carcinoids (5.2 cm), 20 with sporadic insulinomas (1.4 cm), 2 with insulinoma/multiple endocrine neoplasia type 1 (MEN-1) (4.4 cm), and 1 with a malignant insulinoma (13 cm). Sixteen patients had a nonfunctioning tumor (mean size 5 cm). The following techniques were performed: laparoscopic spleen-preserving distal pancreatectomy (Lap SPDP), laparoscopic distal pancreatectomy with splenectomy (Lap SxDP) and laparoscopic enucleation (Lap En)/laparoscopic excision (Lap E). Lymph node dissection was performed when malignancy was suspected (Strasberg s technique). Evaluation criteria included operative and postoperative factors, pathologic data including R0 or R1 resection (the pancreatic transection margin and all transection margins on the specimen were inked). Long-term outcomes were analyzed by tumor recurrence and patient survival. Results Four cases (8.2%) were converted to open surgery. Overall, Lap SPDP, Lap SxDP, and Lap En/Lap E were performed in 15 (33.3%), 8 (17.8%), and 22 (48.9%) patients, respectively. The operative time and blood loss was significantly lower in the Lap En group compared with the other laparoscopic techniques. The group of patients with malignant tumors undergoing Lap SxDP had a longer operating time and greater blood loss compared with the other distal pancreatectomy (Lap DP) techniques. Overall, the postoperative complications were significantly higher in the Lap En group (42.8%) than in the Lap DP (Lap SPDP+Lap SxDP) group (22%). These complications were mainly pancreatic fistula: 8.7% after Lap DP and 38% after Lap En. The overall morbidity was significantly higher after Lap SPDP (26.7%) than after Lap SxDP (12.5%) owing to the occurrence of splenic complications in the Lap SPDP group without splenic vessel preservation two of seven (28.5%). The means and ranges of hospital stay after Lap SPDP, Lap SxDP, and Lap En/Lap E were 5.9 (5-14), 7.5 (5-12), and 5.5 (5-7) days, respectively (NS). Pathology examination of the specimen showed R0 resection in all patients with malignant PNT. The mean time to resumption of previous activities for patients undergoing Lap DP or Lap En was 3 weeks. There were no postoperative (30 days) or hospital deaths. Conclusions This series demonstrates that LPS is feasible and safe in benign-appearing and malignant neuroendocrine pancreatic tumors (NEPTs). The benefits of minimally invasive surgery were manifest in the short hospital stay and acceptable pancreas-related complications in high-risk patients. LPS can achieve negative tangential margins in a high percentage of patients with malignant tumors. Although surgical cure is rare in malignant NEPTs, significant long-term palliation can be achieved in a large proportion of patients with an aggressive surgical approach.

Intra-operative quick insulin assay to confirm complete resection of insulinomas guided by selective arterial calcium injection (SACI)

BACKGROUND AND AIMS

Insulinomas are rare endocrine disorders. Pre-operatively, conventional imaging techniques often fail to localise the tumor. In addition, due to the lack of quick insulin assays, intra-operative confirmation of complete resection was impossible until recently.

MATERIALS AND METHODS

Six patients with biochemical evidence of an insulinoma underwent pre-operative localisation studies and selective arterial calcium injection (SACI). In addition, insulin was measured before surgery and every 10-15 min after resection of the tumor using a quick insulin assay.

RESULTS

Pre-operative localisation studies identified the tumor correctly as follows: endosonography: three of four, magnetic resonance imaging: two of four and SACI: six of six. Tumors in the head and body were enucleated while those in the tail were resected (n = 2, each). Those three patients, in whom magnetic resonance imaging and/or endosonography could localise the tumors pre-operatively, underwent laparoscopic surgery while the remaining three patients underwent open surgery. Intra-operatively, insulin dropped to normal levels within 20 min in all cases. After a follow-up of 0.8-3 years, all patients remained biochemically cured.

CONCLUSIONS

Pre-operatively, SACI appears to be a very sensitive localisation technique and may be most helpful in guiding the surgeon if conventional imaging techniques fail to localise the tumor. Complete removal of an insulinoma can be reliably predicted using a quick insulin assay.

Laparoscopic pancreatic surgery for islet cell tumors of the pancreas

The experience with laparoscopic pancreatic surgery (LPS) in general, and pancreatic islet cell tumors (ICTs) in particular, is still limited. Because insulinoma is the most prevalent tumor and is mostly benign, single, and curable with surgical excision, it comprises most of the cases. Our experience with 17 cases (10 insulinomas, 2 gastrinomas, 1 nesidioblastoma, 4 nonfunctioning tumors) and those recorded in the literature (93 cases) show that laparoscopic surgery for small, solitary benign islet cell tumors located in the body and tail is feasible and safe and can result in rapid postoperative recuperation and a complication rate comparable or lower than that achieved with open surgery. It duplicates the success rate seen with conventional surgery regarding intraoperative localization and cure of disease. The main morbidity continues to be the occurrence of a fistula (18%), most often after enucleation, but the clinical course is benign in most instances. Preoperative imaging studies are required for localization, and the combined use of biphasic helical computed tomography and endoscopic ultrasonography (US) seems to be cost-effective. The use of laparoscopic US is an integral part of the laparoscopic procedure, and the information achieved is valuable for both confirming localization and decision making concerning the most appropriate surgical procedure. In cases of distal pancreatectomy, splenic salvage, preferably with preservation of splenic vessels, is feasible albeit more demanding and can be achieved in most cases.