1/39. Familial isolated hyperparathyroidism caused by single adenoma: a distinct entity different from multiple endocrine neoplasia.Familial hyperparathyroidism (FHPT) is a hereditary disease where hyperparathyroidism (HPT) is transmitted in an autosomal dominant fashion. FHPT consists of a variety of diseases such as multiple endocrine neoplasia type1 (MEN 1) and type2 (MEN 2), familial isolated hyperparathyroidism (FIHPT) with single adenoma and with multiple adenomas (or hyperplasia), and FHPT with jaw-tumor (FHPT-JT). Isolation of the genes responsible for MEN1, and 2, i.e. MEN1 and RET, respectively, makes it possible to examine the relations among disorders constituting FHPT. We studied germ-line mutations in these 2 genes in a family of FHPT with single parathyroid adenoma. The disorder in this family was proved to be an entity different from MEN1 because no germ-line mutations in MEN1 gene were found in the affected members. The loss of heterozygosity (LOH) at MEN1 gene and PYGM were not found in the abnormal parathyroid in this family, supporting the above conclusion. No mutations in exons 10, and 11 of RET proto-oncogene was found in germ-line dna of the affected member of the family, suggesting no relation to MEN2A. Linkage study excluded the possibility of FHPT-JT syndrome. PRAD1 was not overexpressed in the parathyroid tumors in this family. The relation of this disorder to FIHPT with multiple enlarged parathyroid glands remains to be clarified. A search for the gene(s) predisposing to FIHPT is needed.- - - - - - - - - - ranking = 1keywords = gland (Clic here for more details about this article) |
2/39. multiple endocrine neoplasia type 1: atypical presentation, clinical course, and genetic analysis of multiple tumors.multiple endocrine neoplasia type 1 (MEN1) is characterized by the development of endocrine tumors of the parathyroid and pituitary glands, pancreas, and duodenum. Less frequently occurring tumors associated with MEN1 include non-endocrine tumors such as lipomas and angiofibromas. An increased incidence of thyroid neoplasms, leiomyomas, adrenal cortical hyperplasia, hepatic focal nodular hyperplasia, and renal angiomyolipoma has been noted in the MEN1 population. The pathogenesis of non-neuroendocrine tumors in MEN1 is unknown. We report a complex clinical course and a detailed morphologic and genetic analysis of a series of tumors that developed in a patient with MEN1. All tumors were microdissected and analyzed for loss of heterozygosity of the MEN1 gene. A germline mutation of the MEN1 gene was detected, and deletions of the MEN1 gene were consistently detected in multiple neuroendocrine tumors involving the parathyroid glands and the pancreas and a hepatic neuroendocrine tumor metastasis, as predicted by Knudson's "two hit" hypothesis. Two hits of the MEN1 gene were also detected in esophageal leiomyoma tissue, suggesting that tumorigenesis was directly related to the patient's underlying MEN1. In contrast, follicular thyroid adenoma, papillary thyroid carcinoma, hepatic focal nodular hyperplasia, and adrenal cortical hyperplasia consistently showed retained heterozygosity of the MEN1 gene with flanking markers and an intragenic marker. Therefore, these tumors appear to develop along pathogenetic pathways that are different from classical MEN1-associated tumors.- - - - - - - - - - ranking = 2keywords = gland (Clic here for more details about this article) |
3/39. Giant insulinoma in a patient with multiple endocrine neoplasia-type I: a case report.We report a case of giant cystic insulinoma constituting part of multiple endocrine neoplasia (MEN) type I. A 29-year-old Japanese man presented with a history of recurrent hypoglycemic attacks. Endocrine examination showed hyperinsulinemia discordant with hypoglycemia, and a giant cystic insulinoma (11 x 10 cm) located in the pancreatic tail was detected radiologically. hyperprolactinemia due to pituitary adenoma and hyperparathyroidism due to parathyroid hyperplasia were also present. The insulinoma, prolactinoma and hyperplastic parathyroid gland were surgically removed. Fluorescent microsatellite analysis detected loss of heterozygosity (LOH) in chromosome 11q13 in dna samples from all resected tissues but not from white blood cells. This is a rare case of MEN type I because of the giant cystic insulinoma and the evidence of common LOH detected in all MEN type I tissues.- - - - - - - - - - ranking = 1keywords = gland (Clic here for more details about this article) |
4/39. adult-onset angiofibroma and multiple endocrine neoplasia type I.multiple endocrine neoplasia type 1 (MEN 1) predisposes affected persons to neoplasms of the parathyroid glands, the endocrine pancreas, the anterior pituitary, and the duodenum. We report the first case of adult-onset multiple angiofibromas of the central face associated with MEN 1. Seven siblings also developed adult-onset angiofibromas, none with evidence of tuberous sclerosis. Basic fibroblast growth factor (BFGF) is elevated in many patients with MEN 1 and may play a pathogenetic role.- - - - - - - - - - ranking = 1keywords = gland (Clic here for more details about this article) |
5/39. Thymic carcinoid and parathyroid hyperplasia detection with 99mTc-MIBI men type 1.We report a case of a 35-year-old male, with a history of diarrhea, renal lithiasis with frequent expulsions of calculus and hypercalcemia during the last 2 years. The patient was studied and diagnosed with a multiple endocrine neoplasia type I (MEN I), familiar (mother with MEN I). A scintigraphic study with 99mTc-MIBI was performed in order to localize hyperfunctioning parathyroid glands because of biochemical diagnosis of primary hyperparathyroidism. Double phase 99mTc-MIBI scan detected one hyperfunctioning parathyroid gland and a large anterior mediastinal mass. Subsequent, plain radiograph and CT of the chest showed a soft-tissue mass in that localization. Punch biopsy of the lesion guided by CT revealed malignant cells of neuroendocrine tumor. The tumor was removed and histologically confirmed as a carcinoid within a thymus in a MEN type I syndrome. MEN I patients can benefit from the examination with this agent which can potentially localize not only parathyroid endocrine pathology but also unknown associated tumors.- - - - - - - - - - ranking = 2keywords = gland (Clic here for more details about this article) |
6/39. A novel mutation of the MEN1 gene in a Japanese kindred with familial isolated primary hyperparathyroidism.OBJECTIVE: To determine whether familial isolated hyperparathyroidism (FIHP) is a variant of multiple endocrine neoplasia type 1 (MEN1) we analyzed the MEN1 gene in such a kindred. DESIGN AND methods: The study included the 70-year-old proband and nine relatives. Blood was drawn for biochemical evaluation and germline mutation analysis by direct sequencing of the MEN1 gene amplified by PCR. A hyperplastic parathyroid gland obtained from a family member served for a loss of heterozygosity (LOH) study. RESULTS: Three members from two generations in this kindred were found to have primary hyperparathyroidism, while none had clinical or biochemical evidence of MEN1, MEN2 or hyperparathyroidism--jaw tumor syndrome. Analysis of germline dna in the proband showed a missense mutation (GGC-->GAC) at codon 305 in exon 7 of the MEN1 gene that predicts an amino acid change from glycine to aspartic acid (G305D). This mutation segregated with primary hyperparathyroidism in the kindred, and, in addition, there were two asymptomatic mutant-gene carriers at relatively advanced ages. In contrast, the mutation was not detected in genomic dna from five unaffected individuals and from 50 healthy subjects. The LOH study showed a loss of the wild-type allele, which confirmed that a functional defect of the MEN1 gene product, menin, is etiological for FIHP. CONCLUSIONS: FIHP is a genetically heterogeneous disease with a subset linked to MEN1, most likely representing a variant of MEN1. The late onset and the reduced penetrance of disease found in this kindred may be related to the site and the type of mutation, although the precise mechanism involved is unknown at present.- - - - - - - - - - ranking = 1keywords = gland (Clic here for more details about this article) |
7/39. Internally shortened menin protein as a consequence of alternative rna splicing due to a germline deletion in the multiple endocrine neoplasia type 1 gene.multiple endocrine neoplasia type 1 (MEN 1) is an autosomal dominantly inherited cancer syndrome (OMIM 131100), with tumours in several endocrine glands. In 1997 the responsible tumour suppressor gene was identified and recently it was shown that menin, its encoded protein, represses JunD-activated gene expression. Although many MEN 1 patients have been investigated both clinically and genetically, no genotype-phenotype correlation has been found yet. The vast majority of MEN1 gene mutations involve point mutations. We describe a patient in whom a 26 base pair deletion in the MEN1 gene, comprising part of exon 3 and part of intron 3, causes activation of a cryptic donor splice site at the beginning of exon 3. This germline mutation results in an in frame deletion of 105 nucleotides in MEN1 gene mRNA, i.e. an internal deletion of 35 amino acids in the menin protein. Since the deleted region of menin has been implicated in binding to JunD, this may explain the tumourigenic effect of this mutation. The knowledge of this MEN1 gene germline defect, may be used for presymptomatic identification of MEN 1 disease gene-carriers among family-members of this proband. This enables early detection of tumour development, timely treatment and genetic counseling.- - - - - - - - - - ranking = 1keywords = gland (Clic here for more details about this article) |
8/39. Bilateral pituitary adenomas occurring with multiple endocrine neoplasia type one.We report a case of synchronous bilateral pituitary adenomas in a patient with multiple endocrine neoplasia type one (MEN1). The patient was previously known to have a pancreatic gastrinoma and had first-degree relatives with MEN1. Both adenomas were concurrently revealed by high-resolution MR imaging of the pituitary gland as part of the investigation of the patient's severe, persistent headaches and elevated serum prolactin level.- - - - - - - - - - ranking = 1keywords = gland (Clic here for more details about this article) |
9/39. A newly recognized germline mutation of MEN1 gene identified in a patient with parathyroid adenoma and carcinoma.We report on a patient with primary hyperparathyroidism, owing to the concurrence of parathyroid adenoma with carcinoma, who had a newly recognized germline mutation of the multiple endocrine neoplasia type 1 gene (MEN1 gene). The patient underwent total parathyroidectomy, and histological examination revealed parathyroid carcinoma and multiple adenoma of the other three glands. Genetic analysis revealed a newly recognized heterozygous germline mutation (842delC, exon 4) of the MEN1 gene. Both imaging studies and laboratory data showed no evidence of MEN1 in the patient. Four family members--three sisters and one daughter--had neither clinical features of MEN1 nor genetic evidence of the MEN1 gene. This is the first report of a germline mutation of the MEN1 gene found in a patient who exhibited the concurrence of parathyroid adenoma with carcinoma, suggesting that long-term hyperactivity of the parathyroids may result in the formation of carcinoma.- - - - - - - - - - ranking = 1keywords = gland (Clic here for more details about this article) |
10/39. growth hormone overproduction in a patient with multiple endocrine neoplasia type I.In a 69-year-old woman with a complicated history of multiple endocrine neoplasia type I (MEN 1), growth hormone overproduction was found without clinical features of acromegaly. zollinger-ellison syndrome was diagnosed at the age of 36 years. Total gastrectomy and partial pancreatectomy were performed. Two years later hypercalcaemia occurred, hyperparathyroidism was suspected and three hyperplastic parathyroid glands were removed. In 1994 the plasma gastrin level was elevated and a computerized tomography of the abdomen revealed a 1.5-cm large pancreatic tumour. Screening of the pituitary functions was unremarkable and a magnetic resonance scan of the pituitary gland showed no abnormalities. In 1995 type II diabetes mellitus was diagnosed. In 1997 basal plasma growth hormone levels were raised and plasma IGF-I levels were alternately high and normal. The patient had no clinical signs of acromegaly, but glucose tolerance testing resulted in a paradoxical rise in growth hormone concentration compatible with the diagnosis of growth hormone overproduction. magnetic resonance imaging of the pituitary gland revealed a microadenoma.- - - - - - - - - - ranking = 3keywords = gland (Clic here for more details about this article) |
| | Next -> |