Focal or diffuse lesions in persistent hyperinsulinemic hypoglycemia of infancy: concerns about interpretation of intraoperative frozen sections

Single incision laparoscopic 90 % pancreatectomy for the treatment of persistent hyperinsulinemic hypoglycemia of infancy

Single incision laparoscopic surgery as a surgical approach in treatment of pancreatic disease has recently been reported in adults. However, its application in persistent hyperinsulinemic hypoglycemia of infancy (PHHI) in children is limited. In this article, we report single incision laparoscopic 90 % pancreatectomy for the treatment of persistent hyperinsulinemic hypoglycemia of infancy. Between July 2011 and February 2015, the single incision laparoscopic 90 % pancreatectomy was performed in three children with PHHI. All patients underwent (18)F-FDOPA PET/CT before the surgeries. The scans showed diffuse physiologic (18)F-FDOPA activity in entire pancreas. All patients were followed up. The levels of blood sugar and insulin were recorded postoperatively. The time required for surgery was 120-230 min, and blood loss was minimal. The hospital stay was 6 days. The duration of postoperative abdominal drainage was 4-5 days. The levels of fasting blood glucose after surgery were higher than those before surgery (4.38-8.9 vs. 0.54-1.8 mmol/L). The levels of fasting insulin after surgery were lower than those before surgery (2.4-5.5 vs. 14-33.3 uU/ml). The duration of follow-up was 4-46 months. During follow-up, the levels of blood glucose and insulin were normal in three patients. There was no recurrence of hypoglycemia after operation in all patients. Single incision laparoscopic 90 % pancreatectomy for children with PHHI is feasible and safe in well-selected cases in the experienced centers.

Enhanced Islet Cell Nucleomegaly Defines Diffuse Congenital Hyperinsulinism in Infancy but Not Other Forms of the Disease

OBJECTIVES

To quantify islet cell nucleomegaly in controls and tissues obtained from patients with congenital hyperinsulinism in infancy (CHI) and to examine the association of nucleomegaly with proliferation.

METHODS

High-content analysis of histologic sections and serial block-face scanning electron microscopy were used to quantify nucleomegaly.

RESULTS

Enlarged islet cell nuclear areas were 4.3-fold larger than unaffected nuclei, and the mean nuclear volume increased to approximately threefold. Nucleomegaly was a normal feature of pediatric islets and detected in the normal regions of the pancreas from patients with focal CHI. The incidence of nucleomegaly was highest in diffuse CHI (CHI-D), with more than 45% of islets containing two or more affected cells. While in CHI-D nucleomegaly was negatively correlated with cell proliferation, in all other cases, there was a positive correlation.

CONCLUSIONS

Increased incidence of nucleomegaly is pathognomonic for CHI-D, but these cells are nonproliferative, suggesting a novel role in the pathobiology of this condition.

Congenital hyperinsulinism in Brazilian neonates: a study of histology, KATP channel genes, and proliferation of β cells

Congenital hyperinsulinism (CHI) is a rare pancreatic β-cell disease of neonates, characterized by inappropriate insulin secretion with severe persistent hypoglycemia, with regard to which many questions remain to be answered, despite the important acquisition of its molecular mechanisms in the last decade. The aim of this study was to examine pancreatic histology, β-cell proliferation (immunohistochemistry with double staining for Ki-67/insulin), and β-cell adenosine triphosphate-sensitive potassium channels genes from 11 Brazilian patients with severe medically unresponsive CHI who underwent pancreatectomy. Pancreatic histology and β-cell proliferation in CHI patients were compared to pancreatic samples from 19 age-matched controls. Ten cases were classified as diffuse form (D-CHI) and 1 as focal form (F-CHI). β-cell nucleomegaly and abundant cytoplasm were absent in controls and were observed only in D-CHI patients. The Ki-67 labeling index (Ki-67-LI) was used to differentiate the adenomatous areas of the F-CHI case (10.15%) from the "loose cluster of islets" found in 2 D-CHI samples (2.29% and 2.43%) and 1 control (1.54%) sample. The Ki-67-LI was higher in the F-CHI adenomatous areas, but D-CHI patients also had significantly greater Ki-67-LI (mean value  =  2.41%) than age-matched controls (mean value  =  1.87%) (P  =  0.009). In this 1st genetic study of CHI patients in Brazil, no mutations or new polymorphisms were found in the 33-37 exons of the ABCC8 gene (SUR1) or in the entire exon of the KCNJ11 gene (Kir 6.2) in 4 of 4 patients evaluated. On the other hand, enhanced β-cell proliferation seems to be a constant feature in CHI patients, both in diffuse and focal forms.

Laparoscopic vs open pancreatectomy for persistent hyperinsulinemic hypoglycemia of infancy

BACKGROUND

Persistent hyperinsulinemic hypoglycemia of infancy (PHHI) is considered the most common cause of persistent neonatal hypoglycemia. The aim of this study is to compare laparoscopic pancreatectomy with open pancreatectomy for PHHI in one center regarding feasibility, safety, and effectiveness.

METHODS

A retrospective chart review was conducted for patients managed for PHHI with either laparoscopic or open pancreatectomy for the period from 2001 to 2007 at King Faisal Specialist Hospital and Research Center (Riyadh, Saudi Arabia). Demographic and clinical data were retrieved. Continuous variables were reported as means, and categorical variables were reported as proportions for each group. Means were compared using Student's t test, and proportions were compared using chi(2) test or Fisher's Exact test where appropriate. A P value less than .05 was considered statistically significant. The study proposal was approved by the Clinical Research Committee and the Research Ethics Committee at our institution.

RESULTS

Eighteen patients were managed with pancreatectomy for PHHI for that period: 10 laparoscopic and 8 open. The 2 groups were comparable regarding age and weight at surgery, sex, procedure duration, hospital stay postoperatively, need for reoperation, and development of diabetes mellitus and mental delay. Extent of resection was significantly higher in the open group (P value = .02), and the laparoscopic group was fed significantly earlier (P value = .001). The mean follow-up for the laparoscopic and the open groups were 20.4 months and 46 months, respectively (P value = .004).

CONCLUSIONS

Laparoscopic pancreatectomy for PHHI is safe and feasible. Our data suggest its effectiveness compared to the open approach.

Laparoscopic pancreatectomy for persistent hyperinsulinemic hypoglycemia of infancy

BACKGROUND

Persistent hyperinsulinemic hypoglycemia of infancy (PHHI) is considered the most common cause of persistent neonatal hypoglycemia. Management of PHHI involves use of medical agents and its failure is an indication of surgical intervention. Traditionally, an open pancreatectomy was the standard of care but recently laparoscopic pancreatectomy was described. We report our experience with laparoscopic pancreatectomy for PHHI for the period from March 2004 to February 2008.

METHODS

A retrospective chart review was conducted for patients managed for PHHI with laparoscopic pancreatectomy for that period. Demographic and clinical data were retrieved. Descriptive data were generated, and SPSS version 10 statistical package (SPSS, Chicago, Ill) was used.

RESULTS

Twelve patients diagnosed with PHHI were managed with laparoscopic pancreatectomy for that period. Median age at procedure was 11.5 months (range, 0.5-89 months). Median extent of pancreatectomy was 90% (range, 85%-95%). There were 2 (16%) conversions to open technique. One patient (8%) required reoperation 3 months after the procedure. Patients were followed up for a median of 23.5 months (range, 3-48 months). Four (33%) were euglycemic with no medications. Three patients remained on octreotide postoperatively to be euglycemic, and 3 patients needed a combination of octreotide and diazoxide. One patient remained euglycemic for 10 months then started on octreotide because of recurrence of hypoglycemia. One patient remained hypoglycemic postoperatively and required reoperation 3 months later to control symptoms. He became diabetic 4 months after reoperation on insulin.

CONCLUSIONS

Our data suggest that laparoscopic pancreatectomy for medically unresponsive PHHI is feasible and safe. Longer follow-up is needed to ascertain effectiveness.

Evaluation of [18F]fluoro-L-DOPA positron emission tomography-computed tomography for surgery in focal congenital hyperinsulinism

CONTEXT

In congenital hyperinsulinism (CHI), the identification and precise localization of a focal lesion is essential for successful surgery.

OBJECTIVE

Our objective was to evaluate the predictive value and accuracy of integrated [18F]fluoro-L-DOPA ([18F]FDOPA) positron emission tomography (PET)-computed tomography (CT) for the surgical therapy of CHI.

DESIGN

This was an observational study.

SETTING

The study was performed in the Department of Pediatric Surgery at a university hospital.

PATIENTS

From February 2005 to September 2007, 10 children with the clinical signs of CHI and an increased radiotracer uptake in a circumscribed area of the pancreas in the [18F]FDOPA PET-CT were evaluated.

INTERVENTIONS

Guided by the [18F]FDOPA PET-CT report, all children underwent partial pancreatic resection, in two cases twice.

MAIN OUTCOME MEASURES

Correlation of the anatomical findings at surgery with the report of the [18F]FDOPA PET-CT, and the results of surgery and clinical outcome were determined.

RESULTS

In nine children the intraoperative situation corresponded exactly to the description of the [18F]FDOPA PET-CT. A limited resection of the pancreas was curative in eight cases at the first surgery, in one case at the second intervention. We observed no diabetes mellitus or exocrine insufficiency in the follow up so far. In one child, hypoglycemia persisted even after two partial resections of the pancreatic head. Histological analysis finally revealed an atypical intermediate form of CHI.

CONCLUSIONS

The integrated [18F]FDOPA PET-CT is accurate to localize the lesion in focal CHI and is a valuable tool to guide the surgeon in limited pancreatic resection.

An ABCC8 gene mutation and mosaic uniparental isodisomy resulting in atypical diffuse congenital hyperinsulinism

OBJECTIVE

Congenital hyperinsulinism (CHI) may be due to diffuse or focal pancreatic disease. The diffuse form is associated with an increase in the size of beta-cell nuclei throughout the whole of the pancreas and most commonly results from recessive ATP-sensitive K(+) channel (K(ATP) channel) mutations. Focal lesions are the consequence of somatic uniparental disomy for a paternally inherited K(ATP) channel mutation with enlargement of the beta-cell nuclei confined to the focal lesion. Some "atypical" cases defy classification and show pancreatic beta-cell nuclear enlargement confined to discrete regions of the pancreas. We investigated an atypical case with normal morphology within the tail of the pancreas but occasional enlarged endocrine nuclei in parts of the body and head.

RESEARCH DESIGN AND METHODS

The KCNJ11 and ABCC8 genes encoding the K(ATP) channel subunits and microsatellite markers on chromosome 11 were analyzed in DNA samples from the patient and her parents.

RESULTS

A mosaic ABCC8 nonsense mutation (Q54X) was identified in the proband. The paternally inherited mutation was present at 90% in lymphocytes and 50% in normal pancreatic sections but between 64 and 74% in abnormal sections. Microsatellite analysis showed mosaic interstitial paternal uniparental isodisomy (UPD) for chromosome 11p15.1.

CONCLUSIONS

We report a novel genetic mechanism to explain atypical histological diffuse forms of CHI due to mosaic UPD in patients with dominantly inherited ABCC8 (or KCNJ11) gene mutations.

The laparoscopic approach toward hyperinsulinism in children

Hyperinsulinemic hypoglycemia (HH) in children requiring surgery is rare. Early HH can be the result of focal or diffuse pancreatic pathology. A number of genetic abnormalities in early HH have been identified, but in the majority of patients no abnormality is found. The sporadic focal and diffuse forms as well the autosomal recessive form are particularly therapy-resistant and demand for early surgery. Preoperative discrimination between focal and diffuse disease in early HH is difficult. 18 F DOPA PET in combination with CT is promising as is laparoscopic exploration of the pancreas. Frozen section biopsy analysis has not been uniformly beneficial. If macroscopically no focal lesion is found, limited laparoscopic distal pancreatectomy provides tissue for definitive pathologic examination. Subsequent near total laparoscopic spleen-saving pancreatectomy surgery is not particularly difficult. Later HH may occur in the context of the MEN-1 syndrome and is then multifocal in nature. In MEN-1 patients, a distal spleen-saving pancreatectomy with enucleation of lesions in the head seems justified. Insulin-producing lesions in non-MEN-1 patients should be enucleated. There should always be a suspicion of malignancy. Also, in older children, surgery for hyperinsulinism should be performed laparoscopically.

Frozen section examination of liver, gallbladder, and pancreas

CONTEXT

Frozen section of the liver is a comparatively frequent request that most often applies to a relatively limited number of situations. The only indication for frozen tissue examination of a gallbladder with any frequency is the presence of a polypoid mucosal lesion or a suspicious thickening of the gallbladder wall. A variety of intraoperative consultations may be applicable during surgery of the pancreas.

OBJECTIVE

To examine the indications and pitfalls regarding the gross examination and frozen section performance for liver, gallbladder, and pancreas.

DATA SOURCES

Author experience and review of the pertinent literature.

CONCLUSIONS

Although indications are relatively straightforward for frozen section of liver and gallbladder, handling of the pancreas specimens for frozen tissue examination is often a cause for a certain degree of anxiety. This situation is the result of a relative rarity of such specimens outside large tertiary referral medical centers coupled with a variety of confounding factors, including the presence of chronic pancreatitis with distortion of the normal structures and the frequent presence of variable degrees of dysplasia. The suboptimal preservation of the frozen tissue adds further angst to the scenario. In this article, the main issues are critically examined in light of the experience of the author and others.

Hyperinsulinisme persistant du nouveau-né et du nourrisson : traitement chirurgical des lésions pancréatiques focales dans 60 cas

Congenital hyperinsulinism of infancy is a severe disease that leads to important brain damage. Two different forms of the disease have been identified by pathologists: a diffuse and a focal form. A specific genetic anomaly identified in focal forms has never been described in diffuse ones. However, for most of authors, failure of medical treatment results in near-total pancreatectomy in all cases, which ends in diabetus. The aim of this retrospective study was to assess the results of elective partial pancreatectomy performed in 60 cases of focal form of hyperinsulinism over the last 18 years. Fifty-eight patients were cured with euglycemia at both fasting and hyperglycaemic tests without insulin-dependent diabetes mellitus. One patient is still in hypoglycaemia from unrecognized lesion; insulin-dependent diabetes mellitus occurred in one case nine years after surgery (a near-total pancreatectomy has been performed because of unknown focal form, in 1985).

Congenital Hyperinsulinism

Most cases of congenital hyperinsulinism (HI) manifest as either a diffuse or focal form. Diffuse HI is characterized by the presence of enlarged islet cell nuclei, defined as those occupying an area 3 times larger than the surrounding nuclei, throughout the pancreas, and usually requires near total pancreatectomy. Focal HI contains, within an otherwise normal pancreas with islet cell nuclei of normal size, a focus of adenomatous hyperplasia characterized by endocrine cell overgrowth occupying more than 40% of a given area. This form of HI is amenable to partial pancreatectomy. The current study assesses whether intraoperative frozen section evaluation can distinguish the 2 forms and guide the extent of pancreatectomy. By frozen section analysis, diffuse HI is diagnosed when enlarged islet cell nuclei are present in random intraoperative biopsies from the head, body, and tail of the pancreas. Focal HI is suggested when random biopsies contain no large islet cell nuclei, prompting a further search for a focal lesion. Fifty-two HI patients who underwent pancreatectomy from October 1, 1998 to September 30, 2002 were reviewed. On permanent sections, 18 were classified as diffuse HI, 30 had focal HI, and 4 could not be categorized as either. Among 18 diffuse HI patients, 17 were correctly diagnosed by frozen section; all underwent near total pancreatectomy. One case was interpreted as not belonging to typical diffuse or focal HI; however, the permanent sections showed diffuse HI. Twenty-six of 30 focal HI cases were correctly diagnosed by frozen section. The remaining 4 focal HI cases posed diagnostic difficulties on frozen sections because of one the following reasons: 1) presence of equivocally large islet cell nuclei or rare truly large islet cell nuclei in areas nonadjacent to the focal lesion, and 2) large and/or ill defined focus of adenomatous hyperplasia. Twenty-one of 30 focal HI patients eventually had 10% to 93% (mean, 41.8%) of their pancreas resected. In addition to cases typical for diffuse and focal HI, there were 4 other cases whose pancreata did not fit well with either category. These pancreata showed islet cell nuclear enlargement, as characteristically seen in diffuse HI, but only in confined areas of the pancreas. Examination of routinely processed tissue confirmed frozen section findings in all 4 cases. Intraoperative frozen section evaluation, therefore, can assume an essential role in identifying patients with focal HI to limit the extent of pancreatectomy. However, a small number of cases with unusual histology warrant caution when performing frozen section evaluation.

Histopathology of congenital hyperinsulinism: retrospective study with genotype correlations

The majority of the most severe cases of congenital hyperinsulinism (HI) are caused by defects in the beta-cell adenosine triphosphate (ATP)-sensitive potassium channel and usually require pancreatectomy to control blood sugar levels. In contrast to the recent advances in understanding the pathophysiology and genetic bases of HI, the histologic classification of this condition remains controversial. A recent proposal to classify the HI pancreata into diffuse and focal forms has drawn much interest because of its relative simplicity and its good correlation with the genetic abnormalities. We undertook a retrospective study to determine whether this classification scheme could be applied to 38 pancreata resected for HI at our institution. We also obtained leukocyte genomic DNA from 29 cases and screened the exons of ABCC8 and KCNJ11 genes for the presence of mutations. Nineteen cases (50.0%) were histologically classified as diffuse HI and 14 cases (36.8%) were categorized as focal form. The mutational analysis revealed that 14 of the 16 diffuse cases analyzed had either homozygous or compound heterozygous mutations of ABCC8 or KCNJ11 and 7 of 10 focal cases had only the paternally inherited mutations, consistent with the previous observations. Two patients (5.3%) had normal pancreatic histology but had persistent hypoglycemia postoperatively, leaving the possibility of residual focal lesion. Three of 38 cases (7.9%) did not fit well into either diffuse or focal category. Two cases differed from the described pattern for the diffuse form in that the nuclear enlargement was confined to a single area of the pancreas. The other case had a focal lesion but beta-cell nuclear enlargement was present in nonadjacent areas. Mutations for typical diffuse or focal HI were not identified in two of these three equivocal cases. We conclude from this study that nearly 90% of HI cases can be classified into either a diffuse or a focal form. However, a small percentage of cases represented a diagnostic challenge.

Surgery of persistent hyperinsulinaemic hypoglycaemia

Hyperinsulinism (HI) is the commonest cause of persistent or recurrent hypoglycaemia in childhood. HI is genetically and phenotypically diverse. Key management issues involve early diagnosis by insuring that appropriate investigations are undertaken at the point of hypoglycaemia, prevention of recurrent hypoglycaemia and clinical, biochemical and genetic characterisation of the HI syndrome. Children with persistent diazoxide resistant HI require investigation at specialist centres to differentiate those with a generalised disorder of the pancreas (diffuse HI; di-HI) from those with localised abnormalities within the pancreas (focal HI; fo-HI). Fo-HI may be managed by selective pancreatic resection of the focal abnormality. Di-HI is only managed by surgery if combination drug therapies are unable to prevent hypoglycaemia. Pancreatic beta-cell dysfunction persists following subtotal pancreatectomy of di-HI.

The outcome in Australian children with hyperinsulinism of infancy: early extensive surgery in severe cases lowers risk of diabetes

AIMS

Hyperinsulinism of infancy (HI) is characterized by unregulated insulin secretion in the presence of hypoglycaemia, often resulting in brain damage. Pancreatic resection for control of hypoglycaemia is frequently resisted because of the risk of diabetes mellitus (DM). We investigated retrospectively 62 children with HI from nine Australian treatment centres born between 1972 and 1998, comparing endocrine and neurological outcome in 28 patients receiving medical therapy alone with 34 who required pancreatic resection to control their hypoglycaemia.

METHODS

History, treatment and clinical course were ascertained from file audit and interview. Risk of DM (hazard ratio) attributable to age at surgery (< vs. > or = 100 days at last pancreatectomy) and extent of resection (< vs. > or = 95%) were calculated using Cox proportional hazards regression and categorical variables compared by the chi2-test. Neurological outcome (normal, mild deficit or severe deficit) was derived from the most authoritative source.

RESULTS

Surgically treated patients had a greater birthweight, earlier presentation and higher plasma insulin levels. Of 18 infants < 100 days and 16 > or = 100 days of age at surgery, four (all > or = 100 days) became diabetic as an immediate consequence of surgery and five (two < 100 days and three > or = 100 days) became diabetic 7-18 years later. Surgery > or = 100 days and pancreatectomy > or = 95% were associated with development of diabetes (HR = 12.61, CI 1.53-104.07 and HR = 7.03, CI 1.43-34.58, respectively). Neurodevelopmental outcome was no different between the surgical and medical groups with 44% overall with neurological deficits. Patients euglycaemic within 35 days of the first symptom of hypoglycaemia (Group A) had a better neurodevelopmental outcome than those still hypoglycaemic > 35 days from first presentation (Group B) (P = 0.007). Prolonged hypoglycaemia in Group B was due either to delayed diagnosis or to need for repeat surgery because of continued hypoglycaemia. Within Group A, medically treated patients (who presented later with apparently milder disease) had a higher incidence of neurodevelopmental deficit (n = 15, four mild, three severe deficit) compared with surgically treated patients (n = 18, two mild, none severe deficit) (P < 0.025).

CONCLUSIONS

Poor neurodevelopmental outcome remains a major problem in hyperinsulinism of infancy. Risk of diabetes mellitus with pancreatectomy varies according to age at surgery and extent of resection. Patients presenting early with severe disease have a better neurodevelopmental outcome and lower risk of diabetes if they are treated with early extensive surgery.