Pancreatic endocrine tumors

Diagnosis of congenital Hyperinsulinism can occur not only in infancy but also in later age: a new flow chart from a single center experience

BACKGROUND

Congenital Hyperinsulinism typically occurs with a neonatal hypoglycemia but can appear even in childhood or in adolescence with different types of glucose metabolism derangements. Current diagnostic algorithms don't take into account cases with a late presentation.

PATIENTS AND METHODS

Clinical and laboratory data of twenty-two subjects diagnosed at Federico II University of Naples have been described: patients have been divided according to the molecular defect into channel defects, metabolic defects and unidentified molecular defects. A particular focus has been made on three cases with a late presentation.

RESULTS AND CONCLUSIONS

Late presentation cases may not be identified by previous diagnostic algorithms. Consequently, it seems appropriate to design a new flow-chart starting from the age of presentation, also considering that late presentation cases can show glucose metabolism derangements other than hypoglycaemic crises such as diabetes, glucose intolerance, postprandial hypoglycaemia and gestational diabetes.

A Single Centre Analysis of Clinical Characteristics and Treatment of Endocrine Pancreatic Tumours

Background. Endocrine Pancreatic Tumours (PENs) are rare and can be nonfunctioning or functioning. They carry a good prognosis overall though high grade lesions show a relatively shorter survival. The aim of the current study is to describe a single centre analysis of the clinical characteristics and surgical treatment of PENs. Patients and Methods. This is a cohort analysis of 40 patients of PENs who underwent surgery at Sir Ganga Ram Hospital, New Delhi, India, from 1995 to 2013. Patient particulars, clinical features, surgical interventions, postoperative outcome, and followup were done and reviewed. The study group was divided based on grade (G1, G2, and G3) and functionality (nonfunctioning versus functioning) for comparison. Results. PENs comprised 6.3% of all pancreatic neoplasms (40 of 634). Twenty-eight patients (70%) had nonfunctioning tumours. Eighteen PENs (45%) were carcinomas (G3), all of which were nonfunctioning. 14 (78%) of these were located in the pancreatic head and uncinate process (P = 0.09). The high grade (G3) lesions were significantly larger in size than the lower grade (G1 + G2) tumours (7.0 ± 3.5 cms versus 3.1 ± 1.6 cms, P = 0.007). Pancreatoduodenectomy was performed in 18 (45%), distal pancreatectomy in 10 (25%), and local resection in 8 (20%) and nonresective procedures were performed in 4 patients (10%). Fourteen patients (35%) had postoperative complications. All G3 grade tumours which were resected had positive lymph nodes (100%) and 10 had angioinvasion (71%). Eight neoplasms (20%) were cystic, all being grade G3 carcinomas, while the rest were solid. The overall disease related mortality attributable to PEN was 14.3% (4 of 28) and for malignant PENs was 33.3% (4 of 12) after a mean follow-up period of 49.6 months (range: 2–137 months). Conclusion. Majority of PENs are nonfunctioning. They are more likely malignant if they are nonfunctioning and large in size, show cystic appearance, and are situated in the pancreatic head. Early surgery leads to good long term survival with acceptable postoperative morbidity.

Contrast enhancement pattern on multidetector CT predicts malignancy in pancreatic endocrine tumours

OBJECTIVES

Preoperative suspicion of malignancy in pancreatic neuroendocrine tumours (pNETs) is mostly based on tumour size. We retrospectively reviewed the contrast enhancement pattern (CEP) of a series of pNETs on multiphasic multidetector computed tomography (MDCT), to identify further imaging features predictive of lesion aggressiveness.

METHODS

Sixty pNETs, diagnosed in 52 patients, were classified based on CEP as: type A showing early contrast enhancement and rapid wash-out; type B presenting even (B1) or only (B2) late enhancement. All tumours were resected allowing pathologic correlations.

RESULTS

Nineteen pNETs showed type A CEP (5-20 mm), 29 type B1 CEP (5-80 mm) and 12 type B2 (15-100 mm). All tumours were classified as well differentiated tumours, 19 were benign (WDt-b), 15 with uncertain behaviour (WDt-u) and 26 carcinomas (WDC). None of A lesions were malignant (12 WDt-b; 7 WDt-u), all B2 lesions were WDC, 7 B1 lesions were WDt-b, 8 WDt-u and 14 WDC; 4/34 (12 %) lesions ≤2cm were WDC. CEP showed correlation with all histological prognostic indicators.

CONCLUSIONS

Correlating with the lesion grading and other histological prognostic predictors, CEP may preoperatively suggest the behaviour of pNETs, assisting decisions about treatment. Moreover CEP allows recognition of malignant small tumours, incorrectly classified on the basis of their dimension.

Differentiating neoplastic from benign lesions of the pancreas: translational techniques

There has been substantial recent progress in our ability to image and sample the pancreas leading to the improved recognition of benign and premalignant conditions of the pancreas such as autoimmune pancreatitis (AIP) and mucinous lesions (mucinous cystic neoplasms [MCN] and intraductal papillary mucinous neoplasms [IPMN]), respectively. Clinically relevant and difficult situations that continue to be faced in this context include differentiating MCN and IPMN from nonmucinous pancreatic cysts, the early detection of malignant degeneration in MCN and IPMN, and accurate differentiation between pancreatic cancer and inflammatory masses, especially AIP. These challenges arise primarily due to the less than perfect sensitivity for malignancy utilizing cytological samples obtained via EUS and ERCP. Aspirates from pancreatic cysts are often paucicellular further limiting the accuracy of cytology. One approach to improve the diagnostic yield from these very small samples is through the use of molecular techniques. Because the development of pancreatic cancer and malignant degeneration in MCN and IPMN is associated with well studied genetic insults including oncogene activation (eg, k-ras), tumor suppressor gene losses (eg, p53, p16, and DPC4), and genome maintenance gene mutations (eg, BRCA2 and telomerase), detecting these molecular abnormalities may aid in improving our diagnostic accuracy. A number of studies have shown the utility of testing clinical samples from pancreatic lesions and bile duct strictures for these molecular markers of malignancy to differentiate between cancer and inflammation. The information from these studies will be discussed with emphasis on how to use this information in clinical practice.

Pancreatic endocrine tumor EUS-guided FNA DNA microsatellite loss and mortality

BACKGROUND

The clinical course of pancreatic endocrine tumors (PET) depends on tumor size, the presence of invasion or metastasis, the Ki-67 index, mitoses per high power field, and mutational damage. Most of this information is not available before surgery for clinical decision making or prognostication.

OBJECTIVE

To evaluate PET EUS-guided FNA (EUS-FNA) microsatellite loss analysis in the context of PET-related mortality.

DESIGN

A single institution retrospective cohort.

PATIENTS

Patients with PET diagnosed by EUS-FNA who underwent DNA microsatellite loss analysis and at least 1 year of follow-up or subsequent death.

INTERVENTION

PET microsatellite loss analysis results and current clinical status were compared.

RESULTS

Twenty-nine patients were included in the final analysis; the mean age of the patients was 57 years, and 10 were women (35%). The mean follow-up was 33.7 months (median 30 months, range 2-66 months). Twelve patients had disease progression, and 8 died, all from disease-specific causes. Malignant PET contained multiple microsatellite losses, with a median fractional allelic loss (FAL) of 0.37 (range 0.12-0.69, interquartile range [IQR] 0.23-0.42), significantly different from benign PET, median FAL 0 (range 0-0.18, IQR 0-0.08, P < .0001). Survival analysis revealed a significant difference in disease recurrence or progression at 2 years (P < .0001) and in the 5-year survival between patients with FAL </=0.2 compared with >0.2 (P < .0001). Logistic regression could not be performed because of the perfect association between an FAL >0.2 and disease status or mortality.

LIMITATIONS

Retrospective design, referral bias, and DNA analysis availability.

CONCLUSIONS

PET EUS-FNA microsatellite loss analysis provides preoperative prognostic information. An FAL >0.2 is not only associated with disease progression but also with mortality.

What should be done in an operating room when an insulinoma cannot be found?

Insulinoma is the most common (functioning) islet cell tumour of the pancreas and is highly curable with accurate localization and precise extirpation of the often benign, solitary lesion. Although previous reports describe high success rates without pre-operative localization, more recent recognition of the overlap among causes of endogenous hyperinsulinism, coupled with the deleterious long-term effects of blind distal pancreatectomy and re-operation, mandate the need for precise pre-operative localization or regionalization of the tumour(s). If these criteria have not been met and the surgeon finds him/herself in the operating room without a localized or regionalized tumour, the operation should be concluded without resection, the diagnosis reconfirmed, and a calcium stimulation test performed. At experienced centres, this can be often carried out within 24-48 h and the patient returned to the operating room for a gradient-guided resection. Intraoperative venous sampling for insulin might be an option in the future but its accuracy has not been validated in sufficient numbers of patients to date.

Advances in the diagnosis and management of hyperinsulinemic hypoglycemia

Hyperinsulinemic hypoglycemia (HH) is a consequence of unregulated insulin secretion by pancreatic beta-cells and is a major cause of hypoglycemic brain injury and mental retardation. Congenital HH is caused by mutations in genes involved in regulation of insulin secretion, seven of which have been identified (ABCC8, KCNJ11, GLUD1, CGK, HADH, SLC16A1 and HNF4A). Severe forms of congenital HH are caused by mutations in ABCC8 and KCNJ11, which encode the two components of the pancreatic beta-cell ATP-sensitive potassium channel. Mutations in HNF4A, GLUD1, CGK, and HADH lead to transient or persistent HH, whereas mutations in SLC16A1 cause exercise-induced HH. Rapid genetic analysis combined with an understanding of the histological features (focal or diffuse disease) of congenital HH and the introduction of (18)F-L-3,4-dihydroxyphenylalanine PET-CT to guide laparoscopic surgery have totally transformed the clinical approach to this complex disease. Adult-onset HH is mostly caused by an insulinoma; however, it has also been reported to present as postprandial HH in patients with noninsulinoma pancreatogenous hypoglycemia syndrome, in those who have undergone gastric-bypass surgery for morbid obesity, and in those with mutations in the insulin-receptor gene.

The impact of preoperative endoscopic ultrasound on the surgical management of pancreatic neuroendocrine tumours

BACKGROUND

Endoscopic ultrasound (EUS) is accurate in diagnosing pancreatic neuroendocrine tumours (PNETs), but its impact on surgical management is unclear.

OBJECTIVE

To determine whether preoperative EUS findings altered the decision for, and extent of, surgery in patients with PNETs.

METHODS

A retrospective review of patients referred for EUS because of suspected PNETs was conducted. The diagnosis of PNETs was confirmed by EUS-guided fine needle aspiration cytology, where indicated, or by surgical histology. EUS findings were compared with computed tomography (CT) findings to determine whether there was an impact on the decision for surgical management.

RESULTS

Fourteen patients (10 women), with a mean age of 44 years, underwent EUS for suspected PNETs. PNETs were seen with CT in 10 of 13 patients (77%) and with EUS in 14 of 14 patients (100%). One obese patient could not fit into the CT scanner. This patient had five PNETs on EUS. Three patients with a normal CT scan were determined to have one or two PNETs on EUS. Three patients with one or two PNETs on CT were found to have five to eight PNETs on EUS. EUS altered the decision for possible surgical management in five of 14 patients (36%), either by identifying a PNET or by finding multiple and multifocal PNETs that were not visualized on CT scans.

CONCLUSION

EUS is useful in the preoperative assessment of PNETs by providing information that significantly influences the decision for surgical intervention or changes the extent of the planned surgery.

Occult sporadic insulinoma: Localization and surgical strategy

Insulinomas continue to pose a diagnostic challenge to physicians, surgeons and radiologists alike. Most are intrapancreatic, benign and solitary. Biochemical diagnosis is obtained and imaging techniques to localize lesions continue to evolve. Surgical resection is the treatment of choice. Despite all efforts, an occult insulinoma (occult insulinoma refers to a biochemically proven tumor with indeterminate anatomical site before operation) may still be encountered. New localization preoperative techniques decreases occult cases and the knowledge of the site of the mass before surgery allows to determine whether enucleation of the tumor or pancreatic resection is likely to be required and whether the tumor is amenable to removal via a laparoscopic approach. In absence of preoperative localization and intraoperative detection of an insulinoma, blind pancreatic resection is not recommended.