Intestinal neuronal dysplasia and its morphometric evidences

The transition zone in Hirschsprung's bowel contains abnormal hybrid ganglia with characteristics of extrinsic nerves

The aganglionic bowel in short-segment Hirschsprung's disease is characterized both by the absence of enteric ganglia and the presence of extrinsic thickened nerve bundles (TNBs). The relationship between the TNBs and the loss of enteric ganglia is unknown. Previous studies have described decreasing numbers of ganglia with increasing density of TNBs within the transition zone (TZ) between ganglionic and aganglionic gut, and there is some evidence of spatial contact between them in this region. To determine the cellular interactions involved, we have analysed the expression of perineurial markers of TNBs and enteric ganglionic markers for both neural cells and their ensheathing telocytes across four cranio-caudal segments consisting of most proximal ganglionic to most distal aganglionic from pull-through resected colon. We show that in the TZ, enteric ganglia are abnormal, being surrounded by perineurium cells characteristic of TNBs. Furthermore, short processes of ganglionic neurons extend caudally towards the aganglionic region, where telocytes in the TNB are located between the perineurium and nerve fibres into which they project telopodes. Thus, enteric ganglia within the TZ have abnormal structural characteristics, the cellular relationships of which are shared by the TNBs. These findings will help towards elucidation of the cellular mechanisms involved in the aetiology of Hirschsprung's disease.

Efficacy of Sox10 Promoter Methylation in the Diagnosis of Intestinal Neuronal Dysplasia From the Peripheral Blood

OBJECTIVES

Intestinal neuronal dysplasia (IND) is a common malformation of the enteric nervous system. Diagnosis requires a full-thickness colonic specimen and an experienced pathologist, emphasizing the need for noninvasive analytical methods. Recently, the methylation level of the Sox10 promoter has been found to be critical for enteric nervous system development. However, whether it can be used for diagnostic purposes in IND is unclear.

METHODS

Blood and colon specimens were collected from 32 patients with IND, 60 patients with Hirschsprung disease (HD), and 60 controls. Sox10 promoter methylation in the blood and the Sox10 expression level in the colon were determined, and their correlation was analyzed. The diagnostic efficacy of blood Sox10 promoter methylation was analyzed by receiver operating characteristic curve.

RESULTS

The blood level of Sox10 promoter methylation at the 32nd locus was 100% (90%-100%; 95% confidence interval [CI], 92.29%-96.37%) in control, 90% (80%-90%; 95% CI, 82.84%-87.83%) in HD, and 60% (50%-80%; 95% CI, 57.12%-69.76%) in IND specimens. Sox10 promoter methylation in the peripheral blood was negatively correlated with Sox10 expression in the colon, which was low in control, moderate in HD, and high in IND specimens (r = -0.89). The area under the curve of Sox10 promoter methylation in the diagnosis of IND was 0.94 (95% CI, 0.874-1.000, P = 0.000), with a cutoff value of 85% (sensitivity, 90.6%; specificity, 95.0%). By applying a cutoff value of 65%, promoter methylation was more indicative of IND than HD.

DISCUSSION

The analysis of Sox10 promoter methylation in the peripheral blood can be used as a noninvasive method for IND diagnosis.

Intestinal Neuronal Dysplasia Type B: An Updated Review of a Problematic Diagnosis

Context.—

Intestinal neuronal dysplasia type B (IND B) is a controversial histopathologic phenotype that has been associated with intestinal dysmotility, either as an isolated condition or in conjunction with established pathologic disorders (eg, Hirschsprung disease). Many factors contribute to the debate over the existence and/or clinical significance of IND B, including a large body of published data based on inconsistent diagnostic criteria and methods, which have fostered many unwarranted conclusions that lack sufficient scientific basis.

Objective.—

To critically analyze existing published data regarding IND B to provide supporting evidence-based diagnostic practice and to stimulate necessary and scientifically sound research.

Data Sources.—

This update focuses on published literature related to the pathology of IND B because without a reliable pathologic diagnosis, studies of epidemiology, pathogenesis, natural history, management, and outcome are all suspect. Problems with existing data are identified explicitly with suggestions as to how future investigations should be designed and evaluated to better understand this entity.

Conclusions.—

Inconsistencies in diagnostic criteria and methods used to define IND B justifiably encumber the universal acceptance of IND B as a neuropathologic etiology for intestinal dysmotility. IND B will remain a controversial diagnosis until rigorous, well-controlled scientific studies are conducted to establish reproducible and reliable diagnostic criteria that reliably translate from one laboratory to another.

Intestinal neuronal dysplasia type B: A still little known diagnosis for organic causes of intestinal chronic constipation

Intestinal neuronal dysplasia type B (IND-B) is a controversial entity among the gastrointestinal neuromuscular disorders. It may occur alone or associated with other neuropathies, such as Hirschsprung's disease (HD). Chronic constipation is the most common clinical manifestation of patients. IND-B primarily affects young children and mimics HD, but has its own histopathologic features characterized mainly by hyperplasia of the submucosal nerve plexus. Thus, IND-B should be included in the differential diagnoses of organic causes of constipation. In recent years, an increasing number of cases of IND-B in adults have also been described, some presenting severe constipation since childhood and others with the onset of symptoms at adulthood. Despite the intense scientific research in the last decades, there are still knowledge gaps regarding definition, pathogenesis, diagnostic criteria and therapeutic possibilities for IND-B. However, in medical practice, we continue to encounter patients with severe constipation or intestinal obstruction who undergo to diagnostic investigation for HD and their rectal biopsies present hyperganglionosis in the submucosal nerve plexus and other features, consistent with the diagnosis of IND-B. This review critically discusses aspects related to the disease definitions, pathophysiology and genetics, epidemiology distribution, clinical presentation, diagnostic criteria and therapeutic possibilities of this still little-known organic cause of intestinal chronic constipation.

Intestinal Neuronal Dysplasia-Like Submucosal Ganglion Cell Hyperplasia at the Proximal Margins of Hirschsprung Disease Resections

Intestinal neuronal dysplasia type B (IND) denotes an increased proportion of hyperplastic submucosal ganglia, as resolved histochemically in 15-μm-thick frozen sections. IND has been reported proximal to the aganglionic segment in patients with Hirschsprung disease (HSCR) and is putatively associated with a higher rate of postsurgical dysmotility. We developed and validated histological criteria to diagnose IND-like submucosal ganglion cell hyperplasia (IND-SH) in paraffin sections and used the approach to study the incidence and clinical and/or genetic associations of IND-SH at the proximal margins of HSCR pull-through resection specimens. Full-circumference paraffin sections from the proximal margins of 64 HSCR colonic pull-through specimens and 24 autopsy controls were immunostained for neuron-specific Hu antigen, and nucleated ganglion cells in each submucosal ganglion were counted. In controls, an age-related decline in the relative abundance of "giant" ganglia (≥7 nucleated Hu-positive [Hu+] ganglion cells) was observed. A conservative diagnostic threshold for IND-SH (control mean ± 3× standard deviation) was derived from 15 controls less than 25 weeks of age. No control exceeded this threshold, whereas in the same age range, IND-SH was observed at the proximal margins in 15% (7 of 46) of HSCR resections, up to 15 cm proximal to the aganglionic segment. No significant correlation was observed between IND-SH and length of or distance from the aganglionic segment, sex, trisomy 21, RET or SEMA3C/D polymorphisms, or clinical outcome, but analysis of more patients, with better long-term follow-up will be required to clarify the significance of this histological phenotype.

Intestinal neuronal dysplasia type B: one giant ganglion is not good enough

In this "Current Practice in Pediatric Pathology" article, 2 experts in the field and an associate editor of Pediatric and Developmental Pathology discuss the definition, diagnosis, clinical significance, and management of intestinal neuronal dysplasia type B. Intestinal neuronal dysplasia type B has constituted a diagnostic challenge ever since its first description more than 30 years ago. Intestinal neuronal dysplasia type B is regarded by many as a subtle malformation of the enteric nervous system that is limited to the submucosal plexus of the colon. The precise etiology remains unknown, and, to date, no specific diagnostic test exists other than morphology. Over time, with increasing experience, obligate pathological features have been adapted and refined, leading to contemporary diagnostic criteria that are enunciated in this review and placed into context with prior published data. Rigorous application of these criteria, under standardized laboratory conditions, is crucial for accurate diagnosis and future advances in this field.

Persistent obstructive symptoms after surgery for Hirschsprung's disease: development of a diagnostic and therapeutic algorithm

BACKGROUND

Although most children with Hirschsprung's disease (HD) do well after pull-through surgery, some continue to have persistent obstructive symptoms that may lead to significant morbidity. The author's goal was to develop an organized algorithm for the workup and ultimate management of these symptoms.

METHODS

All children referred to the author with severe obstructive symptoms after a pull-through for HD were evaluated using an algorithm based on 5 potential etiologies, and appropriate therapeutic interventions were instituted.

RESULTS

A total of 49 children were evaluated over 7 years. Mechanical obstruction was found using rectal examination and barium enema in 7, of which, 2 had resection of a Duhamel spur, and 5 had a repeat pull-through (after failed dilatation). Rectal biopsy results showed aganglionosis in 10, of whom, 8 underwent repeat pull-through, and 2 refused further surgery. Abnormal intestinal motility or intestinal neuronal dysplasia was found proximal to the aganglionic segment in 10 children using colonic and small bowel manometry or laparoscopic biopsies; 4 of these had additional colon resected and repeat pull-through, and 6 were treated with a bowel management routine, cecostomy, or stoma formation. Internal sphincter achalasia was felt to be the primary cause of symptoms in 14, and all were treated with intrasphincteric botulinum toxin. Eight were found not to fall into any of the above groups and were treated medically for presumed functional megacolon; 2 of these ultimately had a colostomy.

CONCLUSIONS

An organized approach to the diagnosis and management of obstructive symptoms in a child after a pull-through for HD permits accurate diagnosis and effective treatment in the majority of cases.

A new hypothesis on the pathogenesis of intestinal pseudo-obstruction by intestinal neuronal dysplasia (IND)

Using morphometry and image analysis, we investigated 17 patients showing intestinal pseudo-obstruction secondary to intestinal neuronal dysplasia (IND) and 20 controls. In addition to an increase in the number and size of the ganglia and the ganglionic cells, we also noted a significant increase in NO synthase-containing ganglionic cells. We found that this enzyme, responsible for the synthesis of nitrous oxide caused by oxidation of L-argynine aminoacid, is a neurotransmitter able to induce smooth muscle relaxation by activating cyclic AMP. If the increase in NO synthase-producing ganglionic cells is responsible for the increase in nitrous oxide production, one can hypothesize that an overproduction of nitrous oxide plays a role in the pathogenesis of intestinal pseudo-obstruction secondary to neuronal dysplasia. As NO synthase can be blocked, as was demonstrated by giving L-methil-arginine or N-G-nitro-L-argynine, it might be possible to treat intestinal pseudo-obstruction caused by intestinal neuronal dysplasia at the pharmacological level.

Neuropathology of paediatric chronic intestinal pseudo-obstruction and related animal models

Chronic intestinal pseudo-obstruction (CIP) in paediatric patients is due to heterogeneous aetiologies that include primary disorders of the enteric nervous system. These conditions are poorly delineated by contemporary diagnostic approaches, in part because the complex nature of the enteric nervous system may shelter significant physiological defects behind subtle or quantitative anatomical changes. Until recently, relatively few experimental animal models existed for paediatric CIP. However, the availability of rodent models, particularly novel mutants created in the last few years by genetic manipulations, has brought unprecedented opportunities to investigate molecular, cellular, physiological, and histological details of enteric neuropathology. Information gleaned from studies of these animals is likely to change diagnostic and therapeutic approaches to paediatric CIP and related conditions.

Rectal mucosal biopsy compared with laparoscopic seromuscular biopsy in the diagnosis of intestinal neuronal dysplasia in children with slow-transit constipation

BACKGROUND/PURPOSE

Intestinal neuronal dysplasia (IND) as a cause for severe chronic constipation remains controversial. The aim of this study is to examine the correlation between a deficiency of substance P (SP) immunoreactive nerve fibers in the colon and enzyme histochemistry of rectal biopsies in children with slow-transit constipation.

METHODS

Fifty children with intractable constipation have been assessed by rectal biopsies examined with histochemical staining for lactate dehydrogenase, and 32 children among those 50 have been studied by laparoscopic seromuscular biopsy of the colon labelled with antibodies to SP using immunofluorescence methods.

RESULTS

Four children have evidence of IND. Fifteen children, including all 4 IND cases, showed a deficiency of SP immunoreactivity. There is a significant correlation between giant ganglia and SP deficiency (P <.01).

CONCLUSION

This study is attempting to propose that a deficiency of SP immunoreactivity in colonic circular muscle nerves may be used as a histologic marker for slow-transit constipation and that IND may be a small subset of patients with SP deficiency.

Slow-transit constipation in childhood

BACKGROUND/PURPOSE

Intestinal neuronal dysplasia (IND) as a cause for severe chronic constipation remains controversial. The authors have identified a deficiency of substance P (SP) immunoreactivity in the colonic nerve fibres of some children with severe constipation, and aim to correlate this with clinical features and transit studies.

METHODS

Over 100 children with intractable constipation with or without soiling have been assessed by clinical questionnaire, nuclear transit study, and laparoscopic seromuscular biopsy of the colon labelled with antibodies to SP and vasoactive intestinal peptide (VIP) using immunofluorescence.

RESULTS

More than 30% of children had delayed passage of meconium, and symptoms of constipation appeared by the age of 1 year in 63%. More than 80% had significant delay in colonic transit, and of these, about 80% had reduced SP immunoreactivity in the axons of the colonic circular muscle. A further 6% had heterotopic ganglion cells or hypoplastic ganglia on routine histology.

CONCLUSIONS

In children with intractable constipation, features of early onset and delayed colonic transit correlated with deficiency of SP in myenteric axons. The authors propose that deficient SP immunoreactivity may be used as a histological marker for severe constipation. Defective excitatory neuromuscular transmission may be the cause of slow colonic transit.

Morphometric determination of the methodological criteria for the diagnosis of intestinal neuronal dysplasia (IND B)

Intestinal neuronal dysplasia of the submucous plexus (IND B) is an indicator of a developmental abnormality of vegetative gut innervation. It is the mildest form of an inborn error of intestinal innervation. The diagnosis of IND B does not result in a functional conclusion or clinical recommendation but is often accompanied by oligoneuronal hypoganglionosis of the myenteric plexus or an aganglionosis of the rectum. The aim of this study was to demonstrate by morphometric means a way in which the diagnosis of IND B could be made much more reliable. In 20 control subjects, 40 IND B cases and 10 hypoganglionoses with IND B, it was shown that a specific nerve cell staining (e.g. Lactic dehydrogenase, Succinic dehydrogenase, Diaphorase reaction or an immunohistochemical nerve cell staining) was necessary for diagnosis. Cross sections of giant ganglions and cross sections with large nerve cell numbers (> 7 nerve cell profiles) were the most reliable diagnostic criteria. The morphometric examinations were performed with an optic electronic image analysis system. Biopsy serial sections of the rectum-mucosa that contained submucosa demonstrated that 30-40% of the sections contained no submucous ganglion. Sixty to 70% of the sections showed ganglia of the submucous plexus. In 100 biopsy sections in subjects with IND B, 20 +/- 5% contained giant ganglions cross sections. In the patients with hypoganglionosis of the submucous plexus, 55 +/- 4% sections had no ganglion and 18 +/- 3% had giant ganglion cross sections. The data demonstrate that for a reliable diagnosis of IND B, at least 30 sections are necessary, stained with a dehydrogenase reaction that contain a minimum of 4 giant ganglion cross sections. These data demonstrate that IND B is not a qualitative diagnosis as Hirschsprung's disease but rather a quantitative diagnosis.

Innervation patterns of the rectal pouch and fistula in anorectal malformations: a preliminary report

The innervation patterns of the rectal pouch and fistula of 52 children with anorectal malformations were investigated. Posterior sagittal anorectoplasty was used for intermediate and high anomalies; for the latter it was combined with an abdominal approach. Perineoproctoplasty was performed for low anomalies. The specimens were investigated by acetylcholinesterase staining, lactate dehydrogenase, and succinyldehydrogenase reaction. They consisted of fistula material only in 23 patients and of parts of the rectal pouch in 29. Fourty-four patients (84.6%) had follow-up, and information of bowel movements and continence was obtained after a mean of 3.3 years. Abnormal innervation patterns were found in 96% of the specimens. All fistulas were found to be aganglionic, including the adjacent part of the rectum involving the internal sphincter equivalent. Classical aganglionosis was found in 31% of the rectal pouch specimens, hypoganglionosis in 38%, neuronal intestinal dysplasia (NID) type B in 14%, and dysganglionosis in 10%. All patients with severe constipation or soiling at the time of follow-up had some histopathological correlation. Of the 25 patients for whom the specimens had consisted of rectal pouch material, nine (31%) had severe constipation. All four patients with a low-type malformation who had follow-up and pathological innervation patterns in the rectal pouch suffered from severe constipation; this was true of only five of the 19 children with intermediate or high malformations (P < .05). However, numerous pathological innervation patterns had been identified in patients who had normal bowel function at the time of follow-up. It is concluded that partial denervation of the rectum may not be the only cause in the pathogenesis of constipation after posterior sagittal anorectoplasty and perineoproctoplasty. The high frequency of neuronal intestinal malformations in the rectal pouch may be related to the higher frequency of bowel disturbances in patients with low malformations, in whom the resection was less radical. However, the clinical course is not necessarily related to specific histopathological findings. In the authors' opinion, the recommendation to use the distal rectal pouch and parts of the fistula in the reconstruction of anorectal malformations should be reconsidered.