Constipation as the presenting symptom in de novo multiple endocrine neoplasia type 2B

Multiple endocrine neoplasia 2B: Differential increase in enteric nerve subgroups in muscle and mucosa

Multiple endocrine neoplasia 2B (MEN2B) is a rare syndrome caused by an activating mutation of the RET gene, leading to enteric gangliomatosis. This child presented with constipation at 1-mo old, was diagnosed with MEN2B by rectal biopsy at 4 mo, had thyroidectomy at 9 mo and a colectomy at 4 years. We studied the extent of neuronal and nerve fibre proliferation and which classes of enteric nerves are affected by examining the colon with multiple neuronal antibodies. Resected transverse colon was fixed, frozen, sectioned and processed for fluorescence immunohistochemistry labelling with antibodies against TUJ1, Hu, ChAT, NOS, VIP, SP and CGRP and cKit. Control transverse colon was from the normal margin of Hirschsprung (HSCR) colon (4-year-old) and a child with familial adenomatous polyposis (FAP, 12 year). Myenteric ganglia were increased in size to as wide as the circular muscle. There was a large increase in nerve cells and nerve fibres. ChAT-, NOS-, VIP- and SP-immunoreactive nerve fibres all increased in the myenteric ganglia. NOS-IR nerves preferentially increased in the muscle, while VIP and SP increased in submucosal ganglia and mucosal nerve fibres. The density of ICC was normal. RET overactivation in MEN2B lead to a large increase in intrinsic nerve fibres in the myenteric and submucosal ganglia, with a relative increase in NOS-IR nerve fibres in the circular muscle and VIP and SP in the submucosal ganglia and mucosa. The changes were associated with severe constipation resulting in colectomy at 4 years.

Identification of intestinal ganglioneuromatosis leads to early diagnosis of MEN2B: role of rectal biopsy

BACKGROUND/PURPOSE

Gastrointestinal symptoms are very common in patients with multiple endocrine neoplasia type 2B (MEN2B) syndrome. Herein, we present a case of intestinal ganglioneuromatosis (IGN) in MEN2B syndrome and a systematic literature review with a special focus on gastrointestinal symptoms prior to the diagnosis of MEN2B.

METHODS

Literature search was performed (years 1966-2015) using the "Pubmed" and "Scopus" databases. Search terms used were gastrointestinal, intestinal and MEN2B.

RESULTS

Literature search revealed 188 publications on MEN2B patients with gastrointestinal symptoms, providing a total of 55 patients including our own case. The far most common gastrointestinal symptom was constipation (72.7%). The onset of gastrointestinal symptoms occurred in 29 out of 55 cases (52.3%) below the age of 1year. However, MEN2B diagnosis was established at a median age of 13.0years (range 0-46years). The histological finding of IGN led to the diagnosis of MEN2B In 15 of 55 patients (27.3%) at a median age of 3years (range 0-31years).

CONCLUSION

Paying close attention to gastrointestinal problems in early childhood and taking a rectal biopsy that precisely screens for IGN offers the chance of diagnosing MEN2B syndrome early in infancy.

Characteristics of chronic megacolon among patients diagnosed with multiple endocrine neoplasia type 2B

BACKGROUND

Gastrointestinal symptoms are frequent in multiple endocrine neoplasia (MEN) 2B and may be related to megacolon.

OBJECTIVE

The objective of this article is to review the clinical features of patients with MEN 2B, particularly megacolon.

METHODS

We used natural language processing of electronic medical records of Mayo Clinic patients over 20 years: Eight patients with definite MEN 2B were identified; of these, four had megacolon. From these patients' records, three others with paper medical records were identified through familial association. We used a standard data sheet to identify features of the disease with particular emphasis on megacolon.

RESULTS

Of the 11 patients identified with MEN 2B, seven (63%) had megacolon, typically presenting with constipation in infancy or megacolon in childhood. In addition, three patients had esophageal manifestations (two achalasia and one Zenker's diverticulum). Megacolon often required surgical intervention for intractable constipation, abdominal distension and discomfort. Histopathological features of resected colon revealed enteric and extrinsic nerve hyperplasia and ganglioneuromas of the submucosal and myenteric plexuses.

CONCLUSIONS

Among patients with MEN 2B, 63% had megacolon. Significant esophageal motor disorders in MEN 2B may affect ∼25% of patients. Any presentation with megacolon should trigger a search for MEN 2B in order to identify the potentially fatal endocrine tumors.

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.

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.

Early diagnosis of multiple endocrine neoplasia type 2B: a challenge for physicians

BACKGROUND

The hereditary form of medullary thyroid carcinoma may occur isolated as a familial medullary thyroid carcinoma (FMTC) or as part of Multiple Endocrine Neoplasia 2A (MEN2A) and 2B (MEN2B). MEN2B is a rare syndrome, its phenotype may usually, but not always, be noted by the physician. In the infant none of the MEN2B characteristics are present, except by early gastrointestinal dysfunction caused by intestinal neuromas. When available, genetic analysis confirms the diagnosis and guides pre-operative evaluation and extent of surgery. Here we report four cases of MEN2B in which the late diagnosis had a significant impact in clinical evolution and, potentially, in overall survival.

CASE REPORT

We report four cases, 2 men and 2 women, with differences in their phenotypes and with a late diagnosis. The first case has a history of severe gastrointestinal obstruction requiring a surgery intervention two days after his birth. The second told had nodules in the oral mucosa and constipation since childhood. The third case referred a history of constipation from birth until 5 months of life. The fourth has had a history of chronic constipation since childhood.

DISCUSSION

New concepts have emerged since the RET oncogene was identified in 1993 as the responsible gene for hereditary medullary thyroid carcinoma. The majority of MEN2B individuals have M918T mutation in the exon 16 of RET, with a few cases having a mutation A883F or the association of V804M with E805K, Y806C or S904C mutations. The consensus classifies the RET mutation in codon 918 as of highest risk and recommends total thyroidectomy and central lymph node dissection until 6 months after birth. A fast and precise diagnosis is essential to reach these goals. The identification of early manifestations such as intestinal ganglioneuromatosis and oral mucosal neuromas should prompt the physician to initiate an investigation for multiple endocrine neoplasia type 2B.

CONCLUSION

The diagnosis of MEN2B is very important to allow appropriate investigation of associated diseases and to allow counseling and appropriate screening of relatives for a RET mutation. Even patients with MEN2B, which often have typical physical features, may not be properly recognized and be followed as a sporadic case. Based on this, all suspicious cases of multiple endocrine neoplasia should undergo a molecular genetic test.

Evaluation and treatment of constipation in infants and children: recommendations of the North American Society for Pediatric Gastroenterology, Hepatology and Nutrition

Constipation, defined as a delay or difficulty in defecation, present for 2 or more weeks, is a common pediatric problem encountered by both primary and specialty medical providers. The Constipation Guideline Committee of the North American Society for Pediatric Gastroenterology, Hepatology and Nutrition (NASPGHAN) has formulated a clinical practice guideline for the management of pediatric constipation. The Constipation Guideline Committee, consisting of two primary care pediatricians, a clinical epidemiologist, and pediatric gastroenterologists, based its recommendations on an integration of a comprehensive and systematic review of the medical literature combined with expert opinion. Consensus was achieved through Nominal Group Technique, a structured quantitative method. The Committee developed two algorithms to assist with medical management, one for older infants and children and the second for infants less than 1 year of age. The guideline provides recommendations for management by the primary care provider, including evaluation, initial treatment, follow-up management, and indications for consultation by a specialist. The Constipation Guideline Committee also provided recommendations for management by the pediatric gastroenterologist.

An association of multiple endocrine neoplasia 2B, a RET mutation; constipation; and low substance P-nerve fiber density in colonic circular muscle

BACKGROUND

Multiple endocrine neoplasia (MEN) 2B is a rare hereditary syndrome that results from an activating mutation of the RET proto-oncogene. The RET gene is involved in the development of the enteric nervous system. Patients with MEN 2B have enlarged enteric ganglia and may be affected by gastrointestinal dysmotility. A deficiency of the neurotransmitter substance P (SP) has been identified in both pediatric and adult patients with chronic constipation.

METHODS

Three patients, in whom constipation was the presenting symptom and MEN 2B had been provisionally diagnosed, underwent genetic analysis. Seromuscular colonic biopsies were taken for immunofluorescence imaging in all 3 patients. A retrospective review of the patient notes was undertaken.

RESULTS

All 3 patients had constipation refractory to conservative treatment. Genetic analyses in the 3 patients confirmed an identical RET mutation (Met918Thr). Immunofluorescence imaging in all 3 patients identified grossly enlarged myenteric plexus ganglia but surprisingly a low density of SP-labeled nerve fibers in the colonic circular muscle. Nitric oxide synthase and vasoactive intestinal peptide labeling were not reduced.

CONCLUSION

The results show an association between MEN 2B and its most common RET mutation, colonic dysmotility, and low density of SP in the colonic circular muscle. Larger numbers of patients need to be studied to investigate whether low SP is primarily associated with the constipation or RET mutation and if it is a common feature of MEN 2B.

Multiple endocrine neoplasia type 2B diagnosed on suction rectal biopsy in infancy: a report of 2 cases

Suction rectal biopsies in a newborn and a 10-month-old infant presenting with intestinal obstruction showed marked increase in neurons and nerve bundles in the submucosa. Although there were no syndromic features or a positive family history, mutation analysis of the RET proto-oncogene showed a de novo germline Met918Thr mutation in both patients, confirming the diagnosis of multiple endocrine neoplasia type 2B (MEN 2B). Thyroidectomy was performed at 9 and 14 months, showing medullary carcinoma and focal prominent C-cell hyperplasia, respectively. These 2 cases are presented to emphasize that when the submucosal plexus is obviously and prominently increased in suction rectal biopsies, diffuse intestinal ganglioneuromatosis should be considered. As this can be associated with genetic conditions, especially MEN 2B, it is crucial that further investigations be performed to ensure proper patient management, such as early thyroidectomy.

Chronic constipation in children: organic disorders are a major cause

Diagnostic tools for paediatric chronic constipation have been limited, leading to over 90% of patients with treatment-resistant constipation being diagnosed with chronic idiopathic constipation, with no discernible organic cause. Work in our institution suggests that a number of children with intractable symptoms actually have slow colonic transit leading to slow transit constipation. This paper reviews recent data suggesting that a significant number of the children with chronic treatment-resistant constipation may have organic causes (slow colonic transit and outlet obstruction) and suggests new approaches to the management of children with chronic treatment-resistant constipation.

Constipation in infants and children: evaluation and treatment. A medical position statement of the North American Society for Pediatric Gastroenterology and Nutrition

BACKGROUND

Constipation, defined as a delay or difficulty in defecation, present for 2 or more weeks, is a common pediatric problem encountered by both primary and specialty medical providers.

METHODS

The Constipation Subcommittee of the Clinical Guidelines Committee of the North American Society for Pediatric Gastroenterology and Nutrition has formulated clinical practice guidelines for the management of pediatric constipation. The Constipation Subcommittee, consisting of two primary care pediatricians, a clinical epidemiologist, and pediatric gastroenterologists, based its recommendations on an integration of a comprehensive and systematic review of the medical literature combined with expert opinion. Consensus was achieved through Nominal Group Technique, a structured quantitative method.

RESULTS

The Subcommittee developed two algorithms to assist with medical management, one for older infants and children and the second for infants less than 1 year of age. The guidelines provide recommendations for management by the primary care provider, including evaluation, initial treatment, follow-up management, and indications for consultation by a specialist. The Constipation Subcommittee also provided recommendations for management by the pediatric gastroenterologist.

CONCLUSIONS

This report, which has been endorsed by the Executive Council of the North American Society for Pediatric Gastroenterology and Nutrition, has been prepared as a general guideline to assist providers of medical care in the evaluation and treatment of constipation in children. It is not intended as a substitute for clinical judgment or as a protocol for the management of all patients with this problem.