[Hypoganglionosis as a cause of chronic constipation]

Congenital Myenteric Hypoganglionosis

Congenital myenteric hypoganglionosis is a rare developmental disorder characterized clinically by severe and persistent neonatal intestinal pseudoobstruction. The diagnosis is established by the prevalence of small myenteric ganglia composed of closely spaced ganglion cells with sparse surrounding neuropil. In practice, the diagnosis entails familiarity with the normal appearance of myenteric ganglia in young infants and the ability to confidently recognize significant deviations in ganglion size and morphology. We review clinical, histologic, and immunohistochemical findings from 12 patients with congenital myenteric hypoganglionosis in comparison with similar data from age-matched controls and clearly delineate the diagnostic features of the condition. Practical guidelines are provided to assist surgical pathologists, who are likely to encounter this condition only infrequently. The diagnosis typically requires full-thickness intestinal biopsy as the abnormality is confined to the myenteric plexus in many patients. Immunohistochemistry for Hu C/D may be used to confirm hypoganglionosis. Reduced staining for calretinin and NeuN implicates a selective deficiency of intrinsic primary afferent neurons in this disease.

Classification and diagnostic criteria of variants of Hirschsprung's disease

"Variants of Hirschsprung's disease" are conditions that clinically resemble Hirschsprung's disease (HD), despite the presence of ganglion cells in rectal suction biopsies. The diagnosis and management of these patients can be challenging. Specific histological, immunohistochemical and electron microscopic investigations are required to characterize this heterogeneous group of functional bowel disorders. Variants of HD include intestinal neuronal dysplasia, intestinal ganglioneuromatosis, isolated hypoganglionosis, immature ganglia, absence of the argyrophil plexus, internal anal sphincter achalasia and congenital smooth muscle cell disorders such as megacystis microcolon intestinal hypoperistalsis syndrome. This review article systematically classifies variants of HD based on current diagnostic criteria with an additional focus on pathogenesis, epidemiology, clinical presentation, management and outcome.

Novel classification and pathogenetic analysis of hypoganglionosis and adult-onset Hirschsprung's disease

BACKGROUND AND AIMS

Researchers have not clearly described the clinical and pathogenetic features of hypoganglionosis and adult-onset Hirschsprung's disease, which cause pseudo-obstruction or intractable constipation. We conducted this study to explore these features of hypoganglionosis and adult-onset Hirschsprung's disease in Korean patients.

METHODS

We enrolled 24 patients pathologically confirmed as having hypoganglionosis and 11 as having adult-onset Hirschsprung's disease. We recruited 26 subjects who had undergone operation for nonobstructive colon cancer and 45 healthy volunteers as controls. We described their clinical features, investigated ganglion cells and interstitial cells of Cajal (ICC), and analyzed RET, EDNRB, EDN3, and SOX10 genes.

RESULTS

We classified hypoganglionosis patients into two groups: type I (focal type, n = 13), with focally narrowed transition zone (TZ); and type II (diffuse type, n = 11), without transition zone. Hypoganglionosis patients had significantly fewer ganglion cells than the controls, and those cells were scarcer in the transition zone than in the proximal dilated area (P < 0.05). The ICC numbers in both diseases were significantly lower than in controls; however, they were similar between transition zone and the proximal dilated area in hypoganglionosis. In adult-onset Hirschsprung's disease, two significant intronic RET polymorphic variants, IVS14-24G>A and IVS19+47T>C, were significantly associated with adult-onset Hirschsprung's disease (P = 0.0122 and 0.0295, respectively), but not with hypoganglionosis.

CONCLUSIONS

Hypoganglionosis and adult-onset Hirschsprung's disease have different pathophysiologic characteristics, although their clinical presentations are similar. We suggest that there are two subgroups of hypoganglionosis: those with or without a focally narrowed transition zone with a profoundly diminished number of ganglion cells.

Ganglia/nerve fibers ratio correlates with the need for surgery in patients diagnosed with Hirschsprung's disease allied disorder (HAD)

Treatment in Hirschsprung's disease allied disorder (HAD) is surgical. In HAD, surgery is always a question. We investigated the value of ganglia/nerve fibers ratio in prediction of the need for invasive procedures in HAD. Sections of full thickness bowel specimens of 14 patients were stained with antibodies marking ganglia (Anti-Neuron-Specific Enolase, Anti-NSE) and marking nerve fibers (S-100). Six out of seven patients indicated for surgery had low ganglia/nerve fibers ratio. Five out of seven patients, not showing the need for surgery, had high ganglia/nerve fibers ratio. We propose that a lower ganglia/nerve fiber ratio can be used as a predictor of increased need for surgery in HAD.

[Twenty years diagnostic competence center for Hirschsprung's disease in Basel]

BACKGROUND

The experience gained by the Basel Hirschsprung Competence Center over 20 years is presented.

MATERIALS AND METHODS

A total of 19,365 rectal mucosal biopsies were investigated in the 20 years between 1987 and 2006. All biopsies of rectal mucosa originated from 6,615 children aged between 1 week and 4 years. Biopsies were collected in teaching hospitals all over Germany and transported on dry ice by Intercity Courier Service. Serial sections of frozen tissue were made using a cryostat. Enzyme histochemical staining was performed.

RESULTS

A total of 935 cases of Hirschsprung's disease (14%) were observed (769 cases of classical Hirschsprung's disease, 68 total colon aganglionosis, 98 ultrashort rectum aganglionosis). Total colon aganglionosis was found in 1.0% and the frequency of ultrashort Hirschsprung' disease was 1.4%. The quality of the histological results was confirmed by a second independent investigator. There were neither false positive nor false negative diagnoses. Enzyme histochemical staining results were readable within 2 h. Acetylcholinesterase, which is significantly increased in Hirschsprung's disease, was used for nerve fiber staining. Succinic and lactic dehydrogenases and nitric oxide synthase served as confirmatory proof of aganglionosis (elective nerve cell staining of the submucous plexus).

CONCLUSION

Among 100 children with chronic constipation an average of 12 children were diagnosed with Hirschsprung's disease. Of these 2% showed total colon aganglionosis or ultrashort Hirschsprung's disease. Enzyme histochemical diagnosis of Hirschsprung's disease proved 100% reliable and time saving.

The histopathology of gastrointestinal motility disorders in children

Gastrointestinal motility disorders and chronic constipation are common pediatric problems. Symptoms of abdominal discomfort are frequently encountered in the daily practice of pediatricians and pediatric surgeons. Normal peristalsis depends on the interaction between muscles, nerve cells, and tendinous connective tissue of muscularis propria. Malfunction of any of these components results in a motility disorder. Aganglionosis, typically of the left distal colon, is the cause of Hirschsprung disease. Hypoganglionosis constitutes another gastrointestinal motility disorder. In hypoplastic hypoganglionosis, the number of nerve cells and the size of ganglia of the enteric nervous system are reduced, resulting in symptoms similar to aganglionosis. In intestinal neuronal dysplasia type B, submucous plexus development is disturbed. Immaturity of the enteric nervous system, but also ganglioneuromatosis, can be the underlying cause of chronic constipation. Chronic constipation may be caused by a myopathy. Aplasia or atrophy of the tendinous connective tissue of muscularis propria may cause desmosis, which may result in an aperistaltic syndrome. In severe chronic constipation, a histopathological diagnosis of the underlying cause is useful. In the diagnostic approach for most of these causes of chronic constipation, enzyme histochemistry is an efficient tool to complement conventional immunohistochemical and selected molecular technologies. An interdisciplinary approach of a gastrointestinal working group is beneficial in the management of these difficult patients.

Hypoganglionic colorectum in the chick embryo: a model of human hypoganglionosis

INTRODUCTION

The enteric nervous system is an intrinsic network of nerve cells and glia within the gastrointestinal wall, which originates in the vagal and sacral neural tube. The vagal neural tube is known to supply the colorectum with the majority of its nerve cells, and its ablation during early development produces a hypoganglionic colorectum. We hypothesized that the cholinergic nerve activity in the chick embryo hypoganglionic colorectum is decreased similar to the human situation and, therefore, this study is designed to investigate cholinergic innervations in the chick embryo hypoganglionic colorectum.

MATERIALS AND METHODS

Chicken eggs were incubated until embryos reached the 10-12 somite stage. The vagal neural tube was microsurgically ablated and eggs were returned to the incubator until embryos reached E12 and E14. Whole embryos were fixed and embedded in paraffin wax. Transverse sections were cut and immunohistochemistry was performed using a neural crest cell antibody, human natural killer-1 (HNK-1), and a choline acetyltransferase antibody (ChAT).

RESULTS

The results showed that in normal embryos, the colorectum contained many nerve cells (HNK-1) and ChAT-positive nerve cells and fibres, while in embryos with a hypoganglionic colorectum, the number of nerve cells (HNK-1) and ChAT-positive nerve cells and fibres was decreased.

CONCLUSION

Cholinergic nerve activity is decreased as a result of a reduction in nerve cell numbers in the chick embryo colorectum. These results suggest that the cholinergic activity in the hypoganglionic chick model resembles that of human hypoganglionosis.