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H P Neumann

Publications and source records attributed to H P Neumann.

At least 19 recordsLinked to original sources
PubMed2004

[Diagnosis and management of cervical paragangliomas: the Freiburg experience].

BACKGROUND: Paragangliomas of the head and neck represent rare tumors of neural crest origin that arise from chemoreceptors. They are highly vascular neoplasms that are benign in the majority of cases. There are controversial discussions concerning the different treatment options for cervical paragangliomas. PATIENTS: Between January 1992 and November 2003 a total of 13 patients with 15 cervical paragangliomas were treated at the Department of Otorhinolaryngology - Head and Neck Surgery, University of Freiburg. Our study includes eight female and five male patients with a mean age of 39.9 years (range: 20 - 79 years). There were 14 carotid body tumors and one vagal paraganglioma. RESULTS: 14 tumors were resected and one underwent primary radiation. In four patients we noted a total of 8 permanent, postoperative nerve deficits. During follow-up no recurrent tumors were seen. CONCLUSION: Complete surgical removal represents the therapy of choice for the majority of cervical paragangliomas. In cases of multiple head and neck paragangliomas or in patients with underlying diseases, primary radiation should be discussed as a treatment option.

Adult↗
PubMed2004

The genetic basis of pheochromocytoma.

Until very recently, the majority of hereditary pheochromocytomas were related to the MEN 2 and the VHL. In rare instances, hereditary pheochromocytoma was reported in patients with NF1. In addition, nonsyndromic hereditary pheochromocytomas have been reported. Recently, three more genes (SDHD, SDHB, and SDHC) which are all related subunits of the mitochondrial complex II have been identified to cause susceptibility to pheochromocytoma and/or paraganglioma. Hence, mutation analysis of VHL, RET, SDHB, and SDHD is generally recommended in patients with pheochromocytoma regardless of their family history or other features suggestive for a hereditary form. Mutation analysis should start with VHL and RET. However, in the presence of extra-adrenal pheochromocytoma, it may be more useful to screen for VHL, SDHD and SDHB mutations. It is of interest that various different genes can lead to one type of tumor formation. A common pathway (i.e. oxygen sensing) has been shown for VHL and SDHX. However, although several genes that are involved in the pathogenesis of hereditary pheochromocytoma are known, the precise molecular steps in tumorigenesis are widely unknown. In addition, recent data in MEN 2 pheochromocytomas point to a 'second hit' mechanism as a trigger for tumor formation. The molecular pathogenesis of sporadic pheochromocytomas remains obscure [114].

Adrenal Gland Neoplasms↗
PubMed2001

RASSF1A promoter region CpG island hypermethylation in phaeochromocytomas and neuroblastoma tumours.

Deletions of chromosome 3p are frequent in many types of neoplasia including neural crest tumours such as neuroblastoma (NB) and phaeochromocytoma. Recently we isolated several candidate tumour suppressor genes (TSGs) from a 120 kb critical interval at 3p21.3 defined by overlapping homozygous deletions in lung and breast tumour lines. Although mutation analysis of candidate TSGs in lung and breast cancers revealed only rare mutations, expression of one of the genes (RASSF1A) was absent in the majority of lung tumour cell lines analysed. Subsequently methylation of a CpG island in the promoter region of RASSF1A was demonstrated in a majority of small cell lung carcinomas and to a lesser extent in non-small cell lung carcinomas. To investigate the role of 3p TSGs in neural crest tumours, we (a) analysed phaeochromocytomas for 3p allele loss (n=41) and RASSF1A methylation (n=23) and (b) investigated 67 neuroblastomas for RASSF1A inactivation. 46% of phaeochromocytomas showed 3p allele loss (38.5% at 3p21.3). RASSF1A promoter region hypermethylation was found in 22% (5/23) of sporadic phaeochromocytomas and in 55% (37/67) of neuroblastomas analysed but RASSF1A mutations were not identified. In two neuroblastoma cell lines, methylation of RASSF1A correlated with loss of RASSF1A expression and RASSF1A expression was restored after treatment with the demethylating agent 5-azacytidine. As frequent methylation of the CASP8 gene has also been reported in neuroblastoma, we investigated whether RASSF1A and CASP8 methylation were independent or related events. CASP8 methylation was detected in 56% of neuroblastomas with RASSF1A methylation and 17% without RASSF1A methylation (P=0.0031). These results indicate that (a) RASSF1A inactivation by hypermethylation is a frequent event in neural crest tumorigenesis, particularly neuroblastoma, and that RASSF1A is a candidate 3p21.3 neuroblastoma TSG and (b) a subset of neuroblastomas may be characterized by a CpG island methylator phenotype.

Adrenal Gland Neoplasms↗
PubMed2001

Phaeochromocytoma associated with a de novo VHL mutation as form fruste of von Hippel-Lindau disease.

UNLABELLED: Phaeochromocytomas usually occur sporadically but may be associated with dominant inherited cancer syndromes such as multiple endocrine neoplasia type 2 (MEN 2), von Hippel-Lindau disease (VHL) and type 1 neurofibromatosis. We report on a boy presenting at age 8 years with an isolated benign phaeochromocytoma of the left adrenal. Three years later a second adrenal phaeochromocytoma was diagnosed on the right side and removed. His family history was negative. Genetic analysis did not show a mutation in the MEN 2 susceptible proto-oncogene rearranged during transfection; however, we found a germline missense mutation in the VHL gene (nucleotide 695 G to A transversion) which has been described only twice before in the literature. Both parents had normal (wild type) VHL copies indicating that our patient had a de novo germline VHL mutation. Careful clinical evaluation of the patient at 18 years did not reveal any other manifestations of VHL disease. CONCLUSION: Carriers of von Hippel-Lindau germline mutations can present with a form fruste of von Hippel-Lindau disease presenting initially with unilateral phaeochromocytoma and therefore mutation analysis should be carried out.

Adrenal Gland Neoplasms↗
PubMed2001

Laparoscopic surgery for pheochromocytoma.

Because of the excessive production of catecholamines, surgery for pheochromocytoma carries a certain risk that can be reduced by accurate preoperative evaluation and by pretreatment with alpha-blockers. The authors' experience and that of other groups suggests that this inherent risk is not enhanced by the laparoscopic approach, and that, following successful surgery, patients benefit from the minimal invasiveness of this technique. Most surgeons recommend the transperitoneal approach that allows direct access to the adrenal vein, facilitating early ligation. This recommendation does not apply to other pathologies of the adrenal gland. Bilateral adrenal tumors are only seen in patients with familial pheochromocytomas. In this setting, adrenal-sparing surgery should be considered, which can also be performed laparoscopically. Previous adrenal surgery is not a contraindication but will render the procedure more difficult. Laparoscopic excision of paragangliomas is also technically feasible. Laparoscopic adrenal surgery for pheochromocytoma is a difficult and demanding task that must be performed by an experienced surgeon in cooperation with a team of specialists including an internist, endocrinologist, and anesthesiologist.

Adolescent↗
PubMed2001

Von Hippel-Lindau disease masquerading as autosomal dominant polycystic kidney disease.

The diagnostic confusion in differentiating the various causes of renal cystic diseases in adults is well documented. This confusion can include misclassifications between autosomal dominant polycystic kidney disease (ADPKD) and von Hippel-Lindau disease (VHL). We describe such a case of VHL. A review of the literature and of the patients in our database regarding typical features of each disease, mean age of onset, and frequency of these features was undertaken to provide helpful differentiating features. Pancreatic cysts are one differentiating feature. In VHL, pancreatic cysts can occur in 70% of patients, often are multiple, and rarely may cause exocrine or endocrine insufficiency. Pancreatic islet cell tumors occur. In ADPKD, pancreatic cysts are found in only 9% of patients, usually are single and asymptomatic, generally occur in conjunction with cystic liver disease, and are not found in children or unaffected family members. Pancreatic malignancies do not occur with increased frequency in ADPKD. A different pattern, especially in patients without a strong family history of ADPKD, may be a clue to VHL masquerading as ADPKD. Genetic mutation screening of the VHL gene should be used in these patients.

Adult↗
PubMed2001

VHL c.505 T>C mutation confers a high age related penetrance but no increased overall mortality.

BACKGROUND: Germline mutations of the VHL gene cause von Hippel-Lindau syndrome (VHL). In southern Germany, a specific mutation in this gene, c.505 T>C, is one of the most frequent alterations owing to a founder effect. METHODS: This study was conducted to evaluate morbidity, specific clinical risk profile, and mortality among a series of VHL c.505 T/C mutation carriers. A total of 125 eligible subjects carrying VHL c.505 T/C underwent ophthalmoscopy and gadolinium enhanced magnetic resonance imaging of the brain, the spinal cord, and the abdomen. Age related penetrance, morbidity, and mortality were assessed. RESULTS: Frequently observed lesions were phaeochromocytoma (47%), retinal angiomas (36%), haemangioblastoma of the spine (36%), and haemangioblastoma of the brain (16%). Four patients developed renal cell carcinoma. VHL was symptomatic in 47% of subjects; 30% were asymptomatic despite the presence of at least one VHL related tumour and 23% of the carriers had no detectable VHL lesion. Of the 19 patients who had died (15%), 10 died of symptomatic VHL lesions. Overall penetrance by cumulative incidence functions is estimated at 48% by 35 years and 88% by 70 years. In contrast to the only existing published report based on patients with presumably unselected VHL germline mutations, the mortality rate for c.505 T/C mutation carriers is comparable to that of the general population of Germany. CONCLUSIONS: Our results are an important example that a specific genotype, at least in the case of VHL c.505 T/C, can favourably impact on mortality despite a high age related penetrance. Our study also indirectly provides objective data which might be useful to the life and health insurance industry; it would appear that c.505 T>C mutation positive subjects have similar disease specific mortality to that of the general population owing to a combination of phenotype and timely detection of mutation carrier status followed by aggressive clinical screening and, if necessary, treatment.

Adolescent↗
PubMed2001

Reconsideration of biallelic inactivation of the VHL tumour suppressor gene in hemangioblastomas of the central nervous system.

OBJECTIVES: Cerebellar haemangioblastoma occurs sporadically or as a component tumour of autosomal dominant von Hippel-Lindau disease. Biallelic inactivation of the VHL tumour suppressor gene, which is located on chromosome 3p, has been shown to be involved in the pathogenesis of both tumour entities. Mechanisms of VHL inactivation are intragenic mutations, mitotic recombination events, and hypermethylation of the promoter region. The systematic and complete examination of these genetic and epigenetic phenomena in large series of von Hippel-Lindau disease related and sporadic hemangioblastomas has, thus far, not been performed. METHODS: In the largest series to date, 29 von Hippel-Lindau disease associated and 13 sporadic haemangioblastomas were investigated for all suggested inactivating mechanisms of the VHL gene using single strand conformational polymorphism (SSCP), loss of heterozygosity (LOH), and methylation analyses. Additionally, corresponding blood samples of all patients were screened for VHL germline mutations by SSCP and Southern blotting. RESULTS: Germline mutations were identified in 94% of patients with von Hippel-Lindau disease and their tumours and 62% of these hemangioblastomas showed LOH of chromosome 3p. Of the 13 sporadic tumours, 23% showed a single somatic mutation of the VHL gene that was not present in the germline. 3p LOH was identified in 50% of informative sporadic tumours. No von Hippel-Lindau disease related or sporadic tumour demonstrated VHL promoter hypermethylation. CONCLUSIONS: For most von Hippel-Lindau disease related haemangioblastomas, the inactivation or loss of both alleles of the VHL gene, as predicted by the Knudson two hit theory, is required. However, in a subset of tumours including most sporadic haemangioblastomas, the genetic pathways involved in tumorigenesis have yet to be defined and may represent alterations of a different pathway or pathways.

Adolescent↗
PubMed2000

Somatic and occult germ-line mutations in SDHD, a mitochondrial complex II gene, in nonfamilial pheochromocytoma.

Most pheochromocytomas are sporadic but about 10% are though to be hereditary. Although the etiology of most inherited pheochromocytoma is well known, little is known about the etiology of the more common sporadic tumor. Recently, germ-line mutations of SDHD, a mitochondria complex II gene, were found in patients with hereditary paraganglioma. We sought to determine whether SDHD plays a role in the development of sporadic pheochromocytomas and performed a mutation and deletion analysis of SDHD. Among 18 samples, we identified 4 heterozygous sequence variants (3 germ-line, 1 somatic). One germ-line SDHD mutation IVS1+2T>G (absent among 78 control alleles) is predicted to cause aberrant splicing. On reinvestigation, this patient was found to have a tumor of the carotid body, which was likely a paraganglioma. Another patient with malignant, extra-adrenal pheochromocytoma was found to have germ-line c.34G> A (G12S). However, this sequence variant was also found in 1 of 78 control alleles. The third, germ-line nonsense mutation R38X was found in a patient with extra-adrenal pheochromocytoma. The only somatic heterozygous mutation, c.242C>T (P81L), has been found in the germ line of two families with hereditary paraganglioma and is conserved among four eukaryotic multicellular organisms. Hence, this mutation is most likely of functional significance too. Overall, loss of heterozygosity in at least one of the two markers flanking SDHD was found in 13 tumors (72%). All of the tumors that already harbored intragenic SDHD mutations, whether germ-line or somatic, also had loss of heterozygosity. Our results indicate that SDHD plays a role in the pathogenesis of pheochromocytoma. Given the minimum estimated germline SDHD mutation frequency of 11% (maximum estimate up to 17%) in this set of apparently sporadic pheochromocytoma cases and if these data can be replicated in other populations, our observations might suggest that all such patients be considered for SDHD mutation analysis.

Adolescent↗
PubMed2000

Long-term results of laser treatment for retinal angiomatosis in von Hippel-Lindau disease.

PURPOSE: In von Hippel-Lindau disease (VHL), retinal detachment is often a real threat if the retinal angiomas are left untreated. The aim of this trial was to diagnose and treat capillary angiomas early at an asymptomatic stage. METHODS: Since 1983, we have investigated patients with key lesions and those who are at risk for VHL in a multidisciplinary study. Classical retinal angiomas and microangiomas were treated with the Argon laser. Checks during a follow-up of 15 years have provided us with long-term results. RESULTS: We detected 189 retinal angiomas in 97 eyes of 69 patients (105 classical angiomas, including 19 fibrotic angiomas in 15 eyes, 84 microangiomas). During the study, 20 patients (twenty-one symptomatic eyes) entered the study already with a visual impairment. Sixty asymptomatic eyes from 49 patients with a total of 108 retinal angiomas (55 microangiomas and 53 classical angiomas) were treated by us with photocoagulation. Nineteen asymptomatic eyes with angiomas of fibrotic type were observed only. During a mean follow-up of 5.1 years (range: 0.25 - 15; SD: 3.88) observed after treatment, no deterioration of vision occurred in 37 patients treated with photocoagulation. Regular controls showed 5 relapsing angiomas and 9 new angiomas which were successfully coagulated again. New angiomas occurred in those eyes with several angiomas as a predisposition. Patients with a tendency to multiple angiomas need to be seen more frequently because these eyes have a high risk of becoming blind, even in already coagulated angiomas. CONCLUSION: Laser treatment was successful. Early ophthalmological examination of patients with retinal angiomatosis is a great challenge, since these lesions can only be successfully treated at an early stage. Treatment is then effective and safe, but long-term follow-up is necessary. New angiomas occurred in those eyes with several angiomas as a predisposition.

Adolescent↗
PubMed2000

Retinal angiomatosis and von Hippel-Lindau disease.

BACKGROUND: To evaluate the significance of angioma number (single or multiple) for the presence of von Hippel-Lindau (VHL) disease in patients presenting with capillary retinal angioma. METHODS: Forty-one nonrelated patients presenting with capillary retinal angioma were evaluated. An ophthalmic workup, screening for other organ lesions, and molecular genetic screening for a mutation of the VHL gene was performed. The diagnosis of VHL was made on the basis of the personal and family history, the presence of other VHL-associated organ lesions, or the presence of a mutation of the VHL gene. RESULTS: Thirteen patients (32%) presented with a single angioma and 28 patients (68%) presented with multiple angiomas. In 81% of all patients, VHL could be diagnosed. Diagnosis of VHL could be readily made by the personal or family history in 51% of all patients. In another 27% of all patients, VHL disease was evidenced by screening for other VHL-associated lesions. In two patients (3%) VHL could be diagnosed by molecular genetics only. All patients with multiple retinal angiomas had VHL disease and, in 38% of patients with a single angioma, VHL was present. Reasons for a missing family history in patients with VHL disease were the presence of a de novo mutation (15% of VHL patients) or clinical anticipation of VHL disease (18% of VHL patients). CONCLUSION: The presence of multiple retinal angiomas strongly suggests VHL disease, which, however, can be obscured by presence of a de novo mutation or by clinical anticipation of VHL disease in affected families. A single retinal angioma may be sporadic as well as the presenting sign of VHL. Diagnosis and screening for this multitumor syndrome is substantially supported by molecular genetics.

Adolescent↗
PubMed2000

Incidence and clinical relevance of RET proto-oncogene germline mutations in pheochromocytoma patients.

BACKGROUND: Autosomal dominant cancer syndrome--multiple endocrine neoplasia type 2 (MEN 2), may exist more often than expected in patients with pheochromocytoma. Germline mutations identified recently in MEN 2 can be revealed by genetic screening. OBJECTIVE: To evaluate the frequency of RET (rearranged during transfection) mutations in patients with pheochromocytoma. DESIGN AND METHODS: We genetically screened germline mutations in the RET proto-oncogene and clinically re-evaluated patients with pheochromocytoma. A pentagastrin test and other biochemical studies were performed in all patients. SETTING: Department of Internal Medicine and Hypertension, The Medical University of Warsaw, Warsaw, Poland and the Department of Nephrology and Hypertension, Albert Ludwigs University, Freiburg, Germany. PARTICIPANTS: Seventy seven unselected patients with pheochromocytoma (19 men, 58 women, mean age: 51.55 +/- 1.5 years; pheochromocytoma confirmed histopathologically) out of 162 diagnosed and treated in the years 1957-1998 in the Department of Internal Medicine and Hypertension in Warsaw, Poland. The other 85 patients did not respond to the written invitation. MAIN OUTCOME MEASURES: The finding of RET mutations and diagnosis of MEN 2 in patients with pheochromocytoma. RESULTS: Genetic testing revealed germline mutations in the RET proto-oncogene in six patients (7.8%). All carriers had mutation of exon 11, codon 634: TGC to CGC. In four patients with this mutation, medullary thyroid carcinoma (MIC) was diagnosed and in three cases, surgically treated. Biochemical parameters: parathormone 31.88 +/- 2.87 pg/ml, calcitonin: 0 min 0.23 +/- 0.14 ng/ml; 2 min 0.49 +/- 0.21 ng/ml; 5 min 0.48 +/- 0.21 ng/ml, metoxycatecholamines: 601.62 +/- 42.71 microg/24h, epinephrine: 1.94 +/- 0.17 microg/24h, norepinephrine 13.96 +/- 1.3 microg/24h, carcinoembryonic antigen (CEA) 9.94 +/- 4.3 ng/ml. Ambulatory blood pressure monitoring (ABPM): systolic blood pressure (SBP): 116 +/- 1.9 mmHg, diastolic blood pressure (DBP): 73.7 +/- 0.9 mmHg. Clinical, biochemical and imaging procedures did not reveal any recurrence of pheochromocytoma in the 77 patients studied. CONCLUSIONS: Patients with pheochromocytoma should be genetically screened for mutations of the RET proto-oncogene. These patients should undergo clinical screening for MEN 2. In addition, genetic studies can be useful for the screening of the families of the carriers.

Adrenal Gland Neoplasms↗
PubMed2000

Differential genetic alterations in von Hippel-Lindau syndrome-associated and sporadic pheochromocytomas.

Pheochromocytomas arise sporadically and as a component tumor of the inherited cancer syndromes von Hippel-Lindau disease (VHL), multiple endocrine neoplasia type 2 (MEN 2), and type 1 neurofibromatosis. Germline mutations of the VHL tumor suppressor gene (VHL) are responsible for VHL, and germline RET protooncogene mutations are associated with MEN 2. The present study was conducted to examine a large series of 36 VHL-related pheochromocytomas for somatic VHL and RET gene alterations and loss of heterozygosity (LOH) of markers on chromosome arms 1p, 3p, and 22q. For comparison, the same analyses were performed in 17 sporadic pheochromocytomas. We found no somatic intragenic mutations within VHL and RET in any VHL or sporadic pheochromocytoma, and no pheochromocytoma demonstrated upstream VHL gene hypermethylation. Of interest, we found significantly different LOH frequencies at 3 loci between sporadic and VHL tumors; the more than 91% LOH of markers on 3p and the relatively low frequencies of LOH at 1p and 22q (15% and 21%, respectively) in VHL pheochromocytomas argue for the importance of VHL gene dysregulation and dysfunction in the pathogenesis of almost all VHL pheochromocytomas. In contrast, the relatively low frequency of 3p LOH (24%; P: << 0.0001) and the lack of intragenic VHL alterations compared with the high frequency of 1p LOH (71%; P: = 0.0003) and the moderate frequency of 22q LOH (53%) in sporadic pheochromocytomas argue for genes other than VHL, especially on 1p, that are significant for sporadic tumorigenesis and suggest that the genetic pathways involved in sporadic vs. VHL pheochromocytoma genesis are distinct.

Adrenal Gland Neoplasms↗
PubMed2000

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.

Adult↗