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.

Intestinal neuronal dysplasia

Intestinal neuronal dysplasia type B (IND B) is currently defined as a disease of the submucous plexus of the intestine. The aetiology of IND B remains largely obscure. The congenital origin of IND B is supposed; nevertheless, the findings of IND B associated with chronic intestinal obstruction support the notion that this disease could be caused by a reaction of the enteral nervous system to intestinal obstruction or inflammatory disease either in the fetal or the postnatal period. The treatment of IND type B has no unified concept of treatment. The ultimate clinical diagnosis of IND B should be based on a definitive histological diagnosis relating to clinical symptoms, the course of treatment and long-term follow-up of patients with this dysfunction of intestinal motility, despite the fact that no correlations of the clinical picture, radiological investigation and anorectal manometric studies with IND B have been found so far.

[Modification of Svenson's biopsy of rectal wall in diagnosis of malformations of intramural nervous system in adults]

Thirty-five autopsied specimens of rectum's distal part and anal canal part were studied. It was revealed that length of physiological hypogangliosis zone ranged from 7.5 to 50.0 mm (mean 24.4+/-10.9 mm). With regard to this wide range the modification of transanal Svenson's biopsy of rectal wall was proposed for diagnosis of malformations of intramural nervous system of the colon. The method was used in 21 patients with megacolon. The results demonstrate accuracy and safety of this diagnostic method.

Acetylcholine-related bowel dysmotility in homozygous mutant NCX/HOX11L.1-deficient (NCX-/-) mice-evidence that acetylcholine is implicated in causing intestinal neuronal dysplasia

BACKGROUND/PURPOSE

Homozygous mutant Ncx/Hox11L.1-deficient (Ncx-/-) mice develop mega-ileo-ceco-colon (mega-ICC) with a caliber change in the proximal colon. The authors investigated the mechanism of intestinal dysmotility in these mice.

METHODS

Five-week-old Ncx-/- mice with mega ICC were compared with age-matched BDF1 control mice. Jejunum, ileum, and colon were excised from all mice and 1.0-cm-long strips of each organ, each with a resting tension of 0.5g, were suspended in an organ bath filled with Tyrode's solution at 37 degrees C and bubbled with a mixture of 95% oxygen and 5% carbon dioxide. Contractile responses to acetylcholine chloride (ACh), histamine, serotonin, and barium chloride (BaCl2) were recorded isometrically.

RESULTS

For ACh, Ncx-/- mice had decreased distal colon circular muscle contraction only at lower doses and decreased distal colon longitudinal muscle contraction for all doses compared with controls (P <.05 or P <.01). In the proximal colon, Ncx-/- mice had increased circular muscle contraction only at higher doses and decreased longitudinal muscle contraction only at lower doses compared with controls (P <.01 or P <.05). ACh did not affect jejunum, and there were no significant effects on ileum. There was no response to histamine and serotonin by any part of the bowel, and the response to BaCl2 was the same for both Ncx-/- mice and controls.

CONCLUSIONS

Only ACh differentially affected muscle contraction in Ncx-/- mice in the proximal and distal colon. Thus, ACh is implicated in causing the bowel dysmotility seen in Ncx-/- mice and human IND.

Constipation and intestinal neuronal dysplasia type B: a clinical follow-up study

OBJECTIVE

Intestinal neuronal dysplasia type B (IND B) is one of the gastrointestinal motility disorders with a defined malformation of the parasympathetic submucous and myenteric ganglia. The clinical presentation of IND B is variable, ranging from intestinal obstruction in the neonatal period to acute or chronic constipation in childhood.

METHODS

Between 1993 and 1996, 105 patients (49 females and 56 males) were treated for constipation, and in all of them an IND type B was confirmed histopathologically. Twenty-two neonates, 42 infants to 6 months of age (38% of them were premature, and 5% had additional malformations), and 41 patients to the age of 4 years were included in this study. All 105 patients had been treated conservatively. Treatment consisted of diet in all patients, cisapride in 70% of them, laxatives in 52%, and repeated anal dilatations in 12% of the patients. The mean duration of their treatment lasted from 3 months to 10 months (mean, 6 months).

RESULTS

The clinical follow-up 5 to 9 years later in 89 of the 108 (85%) patients showed daily defecation in 80% of them and every second day in 14% of them. Only 5 (6%) patients experience recurrent constipation, which responds well to diet and laxatives.

CONCLUSIONS

In young patients, constipation related to IND B can be treated successfully by conservative treatment regimens, including diet, laxatives, and prokinetic drugs.

Intestinal neuronal dysplasia

Intestinal neuronal dysplasia (IND) is a clinical condition that resembles Hirschsprung's disease. In the past many years investigators have raised doubts about the existence of IND as a distinct histopathologic entity. One strong piece of evidence that IND is a real entity stems from animal models. Recently, two different HOX11L1 knockout mouse models and a heterozygous endothelin B receptor-deficient rat demonstrated abnormalities of the submucous plexus similar to that observed in human IND. This review describes in detail the diagnostic criteria of IND, staining techniques, correlation between histological findings and clinical symptoms, and management of IND.

Submucosal hypoganglionosis causing chronic idiopathic intestinal pseudo-obstruction

A 39-year-old woman presented with recurrent symptoms suggestive of intestinal obstruction. She was put on total parenteral nutrition (TPN) and consequently developed sepsis and endocarditis. TPN was stopped and a venting enterostomy was performed. Biopsies of mucosa and submucosa were taken at surgery; immunohistochemistry for neuronal proteins, protein gene product 9.5 (PGP 9.5) and the glial S-100-protein was done. Many enlarged nerve fiber strands were found in the submucosa. Few small ganglia containing a small number of nerve cells could be observed, suggesting hypoganglionosis. This patient with chronic idiopathic intestinal pseudoobstruction of neurogenic type had a defect in the submucous plexus, whereas visceral neuropathies are usually characterized by defects of the myenteric plexus with normal submucous plexus.

The development of colon innervation in trisomy 16 mice and Hirschsprungs disease

AIM: To study the colon innervation of trisomy 16 mouse, an animal model for Down’s syndrome, and the expression of protein gene product 9.5 (PGP 9.5) in the stenosed segment of colon in Hirschsprungs disease (HD).

METHODS: Trisomy 16 mouse breeding; cytogenetic analysis of trisomy 16 mice; and PGP 9.5 immunohistochemistry of colons of trisomy 16 mice and HD were carried out.

RESULTS: Compared with their normal littermates, the nervous system of colon in trisomy 16 mice was abnormally developed. There existed developmental delay of muscular plexuses of colon, no submucosal plexus was found in the colon, and there was 5 mm aganglionic bowel aparting from the anus in trisomy 16 mice. The mesentery nerve fibers were as well developed as shown in their normal littermates. Abundant proliferation of PGP 9.5 positive nerve fibers was evealed in the stenosed segment of HD colon.

CONCLUSION: Trisomy 16 mice could serve as an animal model for Hirschsprung’s disease for aganglionic bowel in the distal part of colon. Abundant proliferation of PGP 9.5 positive fibers resulted from extrinsic nerve compensation, since no ganglionic cells were observed in the stenosed segment of the colon in HD. HD has a genetic tendency.

[Intestinal neuronal dysplasia in adults as a cause of chronic constipation: morphometric characterization of colon innervation]

Intestinal neuronal dysplasia (IND) was initially described as a developmental abnormality of the submucous plexus in children. In recent years this abnormality has also been observed in adults with chronic constipation. The aim of this study was a morphometric characterization of this disease. The investigation was performed with 10 adults with IND, compared with 10 healthy control probands. The best diagnostic indicator of IND proved to be the detection of 6-10 giant ganglia with more than 7 nerve cells in 15 biopsy sections. IND is an interesting cause of chronic constipation which can be histologically verified.

Anencephaly-associated aganglionosis

Autopsies of 12 consecutively born infants with anencephaly showed varying degrees of aganglionosis and lateralization defects in four of them. This seemingly regular occurrence of these three defects together suggests that they are caused by an aberration of blastogenesis that results in a polytopic field defect.

Congenital malformations and perinatal morbidity associated with intestinal neuronal dysplasia

A close relation between different forms of dysganglionosis such as intestinal neuronal dysplasia (IND) type B and aganglionosis has been established. No systematic analysis of other malformations and diseases accompanying IND has been made as yet. Congenital malformations and perinatal morbidity were analyzed in 109 patients with IND seen at the Department of Pediatric Surgery in Mainz from 1977 to 1996. IND was associated with Hirschsprung's disease in 47 cases; 22 children with IND had other abdominal malformations, including anal atresia, rectal stenosis, sigmoidal stenosis, ileal atresia, pyloric stenosis, and esophageal atresia. A cystic bowel duplication, a choledochal cyst, and a persisting urachus were also found. Extra-abdominal malformations such as Down's syndrome, congenital diaphragmatic hernia, aortic stenosis, and malformations of vertebral bodies were seen. Twin siblings of children with IND were either healthy (n=3) or died in utero (n=1). Seventeen children with IND developed severe intra-abdominal complications during the perinatal period such as necrotizing enterocolitis (NEC), meconium ileus, or bowel perforations. NEC was frequently associated with preterm birth. Bowel perforations were seen in mature and preterm newborns with IND. Taken together, IND is found in a variety of obstructive bowel diseases. This may support the hypothesis that IND is a secondary phenomenon or that congenital atresias and stenoses of the digestive tract have a pathogenesis similar to that of intestinal innervation disturbances. IND may also be a part of complex malformation patterns since it occurs with a number of extraintestinal and non-obstructive intestinal malformations.

[Prospective study of the transit time in intestinal neuronal abnormalities]

In a prospective study 106 children with intestinal neuronal malformations underwent intestinal transit-time studies. In only 50% of the children with intestinal neuronal dysplasia type B or immature ganglia was the transit time prolonged. On the contrary, hypoganglionosis and heterotopia of the submucous plexus led to severe transport disorders with subsequent bowel resection.

Are giant ganglia a reliable marker of intestinal neuronal dysplasia type B (IND B)?

It has been suggested that giant ganglia are a marker for a developmental bowel disorder, intestinal neuronal dysplasia of the submucosal plexus (IND B), diagnosed in a proportion of patients with severe intractable constipation. Diagnosis of this condition, however, remains controversial with a wide variation in the frequency of diagnosis in different centres. Our aim was to assess the frequency with which giant ganglia could be found in the bowel of individuals who did not give a history of life-long constipation. We also aimed to assess the reproducibility of giant ganglia counts. For this two pathologists independently assessed pieces of normal bowel taken away from the site of the lesion in patients who had undergone surgery for colorectal carcinoma. Giant ganglia containing seven or more ganglion cells were found in 76 and 78% of subjects by each of the two pathologists. There was 1 giant ganglion per 10 ganglia counted in those patients in whom they were identified and 1 giant ganglion per 10.9 ganglia overall. Sections from eight patients in whom there was a history of constipation and/or melanosis coli did not show a greater number of giant ganglia. We conclude therefore that so-called "giant ganglia" are a common feature in the submucosa of normal bowel and that the presence of occasional giant ganglia cannot be considered diagnostic of IND B.

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.

Clinical impact of intestinal neuronal malformations: a prospective study in 141 patients

A prospective study of 141 consecutive patients with intestinal neuronal malformations is presented. The single malformation of the autonomic nervous system that always required surgical intervention was aganglionosis. Giant ganglia, reduced parasympathetic tone, immature ganglia, and hypogenetic or heterotopic nerve cells were seen in all forms of malformations. However, the incidence in specific malformations was variable. Multiple giant ganglia were identified in all patients with intestinal neuronal dysplasia (IND) type B, but also in various other malformations. Heterotopic nerve cells in the myenteric plexus were seen in the proximal segment of 15 of 74 patients (20.3%) with aganglionosis and 5 of 9 patients (55.6%) with hypoganglionosis. A significant impact on symptoms was found for IND type B: 34 (45.9%) of 74 children with aganglionosis had associated IND type B, and these children more frequently developed ileus (P < 0.001) and more often needed a second resection (P < 0.05) compared to those with isolated aganglionosis. This indicates an additive effect of both malformations, and therefore, in these patients an extended resection should be carried out. Twelve of 67 patients (17.9%) without aganglionosis needed resection for untreatable constipation. This included 7 of 9 children with hypoganglionosis, both patients with heterotopia of the myenteric plexus, 1 of 20 with isolated IND type B, and 2 of 12 with reduced parasympathetic tone. None of the patients with immaturity, heterotopia of the submucous plexus, or mild dysganglionosis required surgery. Six children (8.9%) without aganglionosis underwent sphincteromyotomy and 2 with IND type B had a temporary colostomy. At follow-up (mean 2.4 +/- 1.4 years), the outcome in patients with resected aganglionosis was better than in patients who had resections for other malformations; 49 (69%) of 71 patients with aganglionosis were asymptomatic compared to 4 (33.3%) of 12 with other malformations (P < 0.05). It is concluded that some intestinal malformations have a relevant clinical impact. However, the severity of symptoms in the individual patient may not be explained by specific histochemical findings from a limited number of mucosal biopsies. The pathognomonic histochemical criteria of isolated IND type B - immaturity, reduced parasympathetic tone, heterotopia of the submucous plexus, and mild dysganglionosis - rarely require surgical therapy and should be treated conservatively.

Hypogenesis of intestinal ganglion cells: a rare cause of intestinal obstruction simulating aganglionosis

Hypogenesis of intestinal ganglion cells is a rare cause of functional intestinal obstruction showing both diminished numbers of ganglion cells per plexus and immature ganglion cells. We report a case of hypogenesis extending from anus to mid small intestine.