1/6. Expression of vesicular monoamine transporters in endocrine hyperplasia and endocrine tumors of the oxyntic stomach.BACKGROUND: Gastric enterochromaffin-like (ECL) cells selectively express the vesicular monoamine transporter (VMAT) VMAT2, and enterochromaffin (EC) cells the VMAT1 isoform. Aims: We investigated whether VMAT isoform selection indicates the origin of endocrine hyperplasia and neoplasia from oxyntic ECL or EC cells and may be of prognostic significance in different types of gastric carcinoids. methods: Tissue from patients with chronic atrophic gastritis (CAG), Zollinger-Ellison-syndrome (ZES), gastric carcinoids and neuroendocrine carcinoma (NEC) was investigated by immunohistology and in situ hybridization. RESULTS: endocrine cells forming diffuse, linear, and micronodular hyperplasia in CAG and ZES, as well as oxyntic microcarcinoids expressed both VMAT2 and chromogranin a (CgA) but neither VMAT1 nor serotonin. In five of six sporadic carcinoids VMAT2 and CgA but not VMAT1 were detected. One carcinoid was copositive for VMAT1 and serotonin but negative for VMAT2. Electron microscopy confirmed the VMAT2-positive tumors as ECLoma and the VMAT1-immunoreactive carcinoid as EComa. CONCLUSIONS: VMAT2 and VMAT1 are reliable markers for differentiation of gastric endocrine hyperplasia and neoplasia from ECL and EC cells, respectively. The significance of VMAT2 and VMAT1 as prognostic markers lies in the relatively poor prognosis for EComa compared to ECLoma, characterized by VMAT2 positivity. The absence of both VMAT2 and VMAT1 in NEC may indicate poor prognosis.- - - - - - - - - - ranking = 1keywords = hybridization (Clic here for more details about this article) |
2/6. A genotypic and histopathological study of a large Dutch kindred with hyperparathyroidism-jaw tumor syndrome.Familial primary hyperparathyroidism is the main feature of 2 familial endocrine neoplasia syndromes: multiple endocrine neoplasia type 1 (MEN 1) and hyperparathyroidism-jaw tumor syndrome (HPT-JT). The latter is a recently described syndrome that has been associated with ossifying fibroma of the jaw and various types of renal lesions, including benign cysts, Wilms' tumor, and hamartomas. To further illustrate the natural history of this syndrome, we describe a large, previously unreported Dutch kindred in which 13 affected members presented with either parathyroid adenoma or carcinoma; in 5 affected individuals, cystic kidney disease was found. Additionally, pancreatic adenocarcinoma, renal cortical adenoma, papillary renal cell carcinoma, testicular mixed germ cell tumor with major seminoma component, and Hurthle cell thyroid adenoma were also identified. Linkage analysis of the family using MEN1-linked microsatellite markers and mutation analysis excluded the involvement of the MEN1 gene. Using markers from the HPT-JT region in 1q2531, cosegregation with the disease was found, with a maximum logarithm of odds score of 2.41 obtained for 6 markers using the most conservative calculation. Meiotic telomeric recombination between D1S413 and D1S477 was identified in 3 affected individuals, and when combined with previous reports, delineated the HPT-JT region to 14 centimorgan. Combined comparative genomic hybridization and loss of heterozygosity data revealed complex genetic abnormalities in the tumors, suggesting different possible genetic mechanisms for the disease. In conclusion, we report a family with hyperparathyroidism linked to chromosome 1q, and exhibiting several types of renal and endocrine tumors that have not been previously described.- - - - - - - - - - ranking = 1keywords = hybridization (Clic here for more details about this article) |
3/6. Pituitary macroadenoma in a 5-year-old: an early expression of multiple endocrine neoplasia type 1.multiple endocrine neoplasia type 1 (MEN 1) is associated with parathyroid, enteropancreatic, pituitary, and other tumors. The MEN1 gene, a tumor suppressor, is located on chromosome 11. Affected individuals inherit a mutated MEN1 allele, and tumorigenesis in specific tissues follows inactivation of the remaining MEN1 allele. MEN 1-associated endocrine tumors usually become clinically evident in late adolescence or young adulthood, as high levels of PTH, gastrin, or PRL. Because each of these tumors can usually be controlled with medications and/or surgery, MEN 1 has been regarded mainly as a treatable endocrinopathy of adults. Unlike in MEN 2, early testing of children in MEN 1 families is not recommended. We report a 2.3-cm pituitary macroadenoma in a 5-yr-old boy with familial MEN 1. He presented with growth acceleration, acromegaloid features, and hyperprolactinemia. We tested systematically to see whether his pituitary tumor had causes similar to or different from a typical MEN 1 tumor. Germ line dna of the propositus and his affected relatives revealed a heterozygous point mutation in the MEN1 gene, which leads to a His139Asp (H139D) amino acid substitution. The patient had no other detectable germ-line mutations on either MEN1 allele. dna sequencing and fluorescent in situ hybridization with a MEN1 genomic dna sequence probe each demonstrated one copy of the MEN1 gene to be deleted in the pituitary tumor and not in normal dna, proving MEN1 "second hit" as a tumor cause. Gsalpha mutation, common in nonhereditary GH-producing tumors, was not detected in this tumor. We conclude that this pituitary macroadenoma showed molecular genetic features of a typical MEN 1-associated tumor. This patient represents the earliest presentation of any morbid endocrine tumor in MEN 1. A better understanding of early onset MEN 1 disease is needed to formulate recommendations for early MEN 1 genetic testing.- - - - - - - - - - ranking = 1keywords = hybridization (Clic here for more details about this article) |
4/6. monosomy of chromosome 11 in pituitary adenoma in a patient with familial multiple endocrine neoplasia type 1.multiple endocrine neoplasia type 1 (MEN 1) represents an endocrine syndrome characterized by complex pituitary, parathyroid and pancreatic neoplasia. loss of heterozygosity of the specific region 11q13 has been reported in several tumours from patients with MEN 1 inherited disorder. We present a case of a young patient with familial MEN 1 syndrome with a pituitary adenoma exhibiting monosomy of chromosome 11. The patient presented with a large and rapidly growing pituitary adenoma associated with markedly elevated serum PRL levels, progressive bilateral visual loss and hydrocephalus. The resected adenoma was chromophobic, mainly PRL-producing and to a lesser degree immunoreactive for GH. fluorescence in situ hybridization (FISH) using an alpha-satellite centromeric probe detected loss of one chromosome 11 copy in almost all pituitary adenoma cells. Clinical and biochemical studies revealed parathyroid hyperplasia and MRI studies detected a pancreatic tumour in addition to the pituitary adenoma. To our knowledge this is the first study reporting monosomy 11 in pituitary adenoma in a patient associated with familial MEN 1 syndrome.- - - - - - - - - - ranking = 1keywords = hybridization (Clic here for more details about this article) |
5/6. Combined sellar fibrosarcoma and prolactinoma with neuronal metaplasia: report of a case unassociated with radiotherapy.We report the occurrence of a primary pituitary fibrosarcoma causally unrelated to radiotherapy, admixed in association with a prolactin cell pituitary adenoma showing neuronal metaplasia. These unique findings were associated with multiple endocrine neoplasia type 1 (MEN 1). Primary fibrosarcoma involving the sella is a very rare tumor. The majority of cases have been associated with prior irradiation of either a pituitary adenoma or a craniopharyngioma. Pituitary adenoma with neuronal metaplasia is also rare and usually occurs in the setting of acromegaly. Despite the intimate association of both elements in our lesion, no transition of adenoma to sarcoma was demonstrable by immunohistochemistry or in situ hybridization studies.- - - - - - - - - - ranking = 1keywords = hybridization (Clic here for more details about this article) |
6/6. comparative genomic hybridization studies in tumours from a patient with multiple endocrine neoplasia type 1.OBJECTIVE: To identify genetic changes, other than the MEN1 gene, that might be involved in the tumorigenesis and progression of multiple endocrine neoplasia type 1 (MEN1)-related tumours. methods: We used comparative genomic hybridization (CGH) and loss of heterozygosity (LOH) to study tumours from various sites in a patient with MEN1. RESULTS: Gain of genetic material was not found. Frequent losses of genetic material were found in chromosomes 1, 4, 5, 6, 9, 11 and 18. Besides the chromosome 11 where the MEN1 gene is located, the other regions are known to harbour important tumour suppressor genes. CONCLUSIONS: These results suggest the involvement of other cancer-related genes in the tumorigenesis and progression of MEN1 tumours that warrant further investigations.- - - - - - - - - - ranking = 5keywords = hybridization (Clic here for more details about this article) |