Multiple Endocrine Neoplasia Syndrome 2B Research Articles

Current status of familial gastrointestinal polyposis syndromes.

Because of the rarity of familial gastrointestinal cancer-predisposing syndromes, their exploration in literature is not extensive. In this review, an update of the clinicopathological and molecular criteria of gastrointestinal familial polyposis syndromes with potential malignant transformation is performed. In addition, a guide for screening and surveillance was synthesized and a distribution of gene mutations according to the specific syndromes and geographic distribution was included. The following inherited polyposes syndromes were analyzed: familial adenomatous polyposis, the hamartomatous familial polyposes (Juvenile polyposis, Peutz-Jeghers syndrome, Cowden syndrome, Bannayan-Riley-Ruvalcaba syndrome, hereditary mixed polyposis syndrome, Gorlin syndrome, Birt-Hogg-Dube syndrome, neurofibromatosis type I and multiple endocrine neoplasia syndrome 2B), Li-Fraumeni syndrome, and MUTYH-associated adenomatous polyposis. For proper medical care, subspecialization of gastroenterologists, pathologists, and genticists in the field of familial diseases should be introduced in the medical curriculum.

Hamartomatous polyposis syndromes: a review.

Hamartomatous Polyposis Syndromes (HPS) are genetic syndromes, which include Peutz-Jeghers syndrome, Juvenile polyposis syndrome, PTEN hamartoma tumour syndrome (Cowden Syndrom, Bannayan-Riley-Ruvalcaba and Proteus Syndrome) as well as hereditary mixed polyposis syndrome. Other syndromes such as Gorlin Syndrome and multiple endocrine neoplasia syndrome 2B are sometimes referred to as HPS. HPS is characterized by the development of hamartomatous polyps in the gastrointestinal tract as well as several extra-intestinal findings such as dermatological and dysmorphic features or extra-intestinal cancer. The syndromes are rare and inherited in an autosomal dominant manner.The diagnosis of HPS has traditionally been based on clinical criteria, but can sometimes be difficult as the severity of symptoms range considerably from only a few symptoms to very severe cases - even within the same family. De novo cases are also frequent. However, because of the discovery of several associated germline-mutations as well as the rapid development in genetics it is now possible to use genetic testing more often in the diagnostic process. Management of the syndromes is different for each syndrome as extra-intestinal symptoms and types of cancers differs.Clinical awareness and early diagnosis of HPS is important, as affected patients and at-risk family members should be offered genetic counselling and surveillance. Surveillance in children with HPS might prevent or detect intestinal or extra-intestinal complications, whereas in adulthood surveillance is recommended due to an increased risk of cancer e.g. intestinal cancer or breast cancer.

Genetics of the hamartomatous polyposis syndromes: a molecular review

Hamartomatous polyposis syndromes are a heterogeneous group of disorders that are inherited in an autosomal dominant fashion. These syndromes only represent a small number of the inherited gastrointestinal cancer predisposition syndromes. However, many of these syndromes carry a substantial risk for developing colorectal cancer, as well as extra-colonic malignancy. We searched for articles on inherited hamartomatous polyposis syndromes, including familial juvenile polyposis syndrome, Peutz-Jeghers syndrome, PTEN hamartoma tumor syndrome, multiple endocrine neoplasia syndrome 2B, hereditary mixed polyposis syndrome, Cronkhite-Canada syndrome, basal cell nevus syndrome, and neurofibromatosis 1, in PubMed, Embase, and Elsevier ScienceDirect. In this review, we briefly discuss the diagnosis and clinical features of these disorders and the molecular alterations responsible for these syndromes. Given the clinical similarities of these hamartomatous syndromes and the autosomal dominant pattern of inheritance, it is sometimes difficult to differentiate hamartomatous polyps, especially with atypical presentation. The molecular analysis and diagnosis make it possible to identify the subtype of these syndromes. In addition, these tests raise an intriguing possibility that surveillance and early medical intervention will allow for the identification of at-risk patients and the reduction of morbidity and mortality.

Orolabial signs are important clues for diagnosis of the rare endocrine syndrome MEN 2B. Presentation of two unrelated cases

Multiple endocrine neoplasia syndromes (MEN) are genetic disorders with glandular hyperplasia and consecutive malignant neoplasia. MEN type 2B is the least common form of these tumor syndromes. It presents with typical dysmorphic features, mucosal neuromas, ganglioneuromatosis, medullary thyroid carcinoma (MTC) and phaeochromocytoma. The prognosis depends on the presence of MTC. We have surprisingly found two unrelated patients with this syndrome at our department within two weeks. In the medical history of a 17-year-old boy, Crohn's disease had been considered because of abdominal pain and distention. He had marfanoid appearance and previously undergone minor surgeries for a large tongue with neuromas and hypertrophic gums. Two weeks later, a 10-year-old girl presented with a hard palpable mass on her neck. She had thickened lips, neuromas on the tongue and a solitary thyroid nodule. Genetic analysis was carried out in both patients and a heterozygous M918T mutation of the RET proto-oncogene was found. Laboratory tests and imaging studies were consistent with MTC. Phaeochromocytoma was not present. Both patients underwent total thyroidectomy and lymph node dissection. Histological examination confirmed the diagnosis of MTC. In conclusion, the initial diagnosis of MEN 2B should be suspected on the presence of typical facial/oral signs and gastrointestinal symptoms. Hormonal tests and imaging techniques of the thyroid and the adrenals can confirm the clinical diagnosis of MEN 2B and genetic analysis can prove its germline origin.

The Hamartomatous Polyposis Syndromes: A Clinical and Molecular Review

Inherited forms of gastrointestinal cancer have been a major focus of study and advancement over the past decade. Familial adenomatous polyposis and hereditary nonpolyposis colon cancer are the two most common heritable colon cancer syndromes. Inherited polyposis syndromes are characterized by the dominant type of polyp (whether adenomatous or hamartomatous) present and by the polyp's location within the gastrointestinal tract. The hamartomatous polyposis syndromes are characterized by an overgrowth of cells native to the area in which they normally occur. They represent a small but appreciable number of the gastrointestinal inherited cancer predisposition syndromes; it is now known that many of these syndromes carry a substantial risk for developing colon cancer as well as other gastrointestinal and pancreatic cancers. Patients afflicted with these syndromes are also at significant risk for extraintestinal malignancies. Seven inherited hamartomatous polyposis syndromes have been described: familial juvenile polyposis syndrome, Cowden's syndrome, Bannayan-Ruvalcaba-Riley syndrome, Peutz-Jeghers syndrome, basal cell nevus syndrome, neurofibromatosis 1, and multiple endocrine neoplasia syndrome 2B. Hereditary mixed polyposis syndrome is a variant of juvenile polyposis characterized by both hamartomatous and adenomatous polyps. The hamartomatous syndromes occur at approximately 1/10th the frequency of the adenomatous syndromes and account for <1% of colorectal cancer in Northern America. While the diagnosis of these inherited syndromes is primarily clinical, genetic testing is now available for all six syndromes. However, there are a significant number of spontaneous mutations seen in each of the syndromes. The management of these patients necessitates a coordinated multidisciplinary approach. The purpose of this review is to characterize the clinical and pathological features of these syndromes and to review the targets of cancer surveillance. The molecular alterations responsible for the inherited hamartomatous polyposis syndromes will also be discussed.