http://repub.eur.nl/res/aut/26133/ List of Publications en http://repub.eur.nl/static-eur/img/logo.png http://repub.eur.nl http://repub.eur.nl/res/pub/39729/ 2013-03-01T00:00:00Z Most gastrointestinal stromal tumors (GISTs) harbor oncogenic mutations in KIT or platelet-derived growth factor receptor-α. However, a small subset of GISTs lacks such mutations and is termed 'wild-type GISTs'. Germline mutation in any of the subunits of succinate dehydrogenase (SDH) predisposes individuals to hereditary paragangliomas and pheochromocytomas. However, germline mutations of the genes encoding SDH subunits A, B, C or D (SDHA, SDHB, SDHC or SDHD; collectively SDHx) are also identified in GISTs. SDHA and SDHB immunohistochemistry are reliable techniques to identify pheochromocytomas and paragangliomas with mutations in SDHA, SDHB, SDHC and SDHD. In this study, we investigated if SDHA immunohistochemistry could also identify SDHA-mutated GISTs. Twenty-four adult wild-type GISTs and nine pediatric/adolescent wild-type GISTs were analyzed with SDHB, and where this was negative, then with SDHA immunohistochemistry. If SDHA immunohistochemistry was negative, sequencing analysis of the entire SDHA coding sequence was performed. All nine pediatric/adolescent GISTs and seven adult wild-type GISTs were negative for SDHB immunohistochemistry. One pediatric GIST and three SDHB-immunonegative adult wild-type GISTs were negative for SDHA immunohistochemistry. In all four SDHA-negative GISTs, a germline SDHA c.91C>T transition was found leading to a nonsense p.Arg31X mutation. Our results demonstrate that SDHA immunohistochemistry on GISTs can identify the presence of an SDHA germline mutation. Identifying GISTs with deficient SDH activity warrants additional genetic testing, evaluation and follow-up for inherited disorders and paragangliomas. http://repub.eur.nl/res/pub/31054/ 2011-09-01T00:00:00Z Context: Pheochromocytoma-paraganglioma syndrome is caused by mutations in SDHB, SDHC, and SDHD, encoding subunits of succinate dehydrogenase (SDH), and in SDHAF2, required for flavination of SDHA. A recent report described a patient with an abdominal paraganglioma, immunohistochemically negative for SDHA, and identified a causal germline mutation in SDHA. Objective: In this study, we evaluated the significance of SDHA immunohistochemistry in the identification of new patients with SDHA mutations. Setting: This study was performed in the Erasmus Medical Center in Rotterdam (The Netherlands) and the Université Paris Descartes in Paris (France). Methods: We investigated 316 pheochromocytomas and paragangliomas for SDHA expression. Sequence analysis of SDHA was performed on all tumors that were immunohistochemically negative for SDHA and on a subset of tumors immunohistochemically positive for SDHA. Results: Six tumors were immunohistochemically negative for SDHA. Four tumors from Dutch patients showed a germline c.91C→T SDHA gene mutation (p.Arg31X). Another tumor (from France) carried a germline SDHA missense mutation c.1753C→T (p.Arg585Trp). Loss of the wildtype SDHA allele was confirmed by loss of heterozygosity analysis. Sequence analysis of 35 SDHA immunohistochemically positive tumors did not reveal additional SDHA mutations. Conclusions: Our results demonstrate that SDHA immunohistochemistry on paraffin-embedded tumors can reveal the presence of SDHA germline mutations and allowed the identification of SDHA-related tumors in at least 3% of patients affected by apparently sporadic (para)sympathetic paragangliomas and pheochromocytomas. Copyright http://repub.eur.nl/res/pub/21251/ 2010-11-10T00:00:00Z The paraganglion system is composed of a collection of chromaffin cells that is distributed throughout the body. Embryonically, chromaffin cells arise from the neuroectodermal tissue of the neural crest and are thought to migrate along the innervating nerves or vasculature towards their primordial location to form the paraganglia. The largest paraganglion is the adrenal medulla, an important neuroendocrine organ, which is the body’s main source of catecholamines (adrenalin, noradrenalin and dopamine). The adrenal medulla receives input from the sympathetic nervous system through preganglionic fibers upon which it releases its secretions directly into the blood. Besides this adrenal station there are many extra‐adrenal paraganglia that are distributed along the body axis and located in the proximity of ganglia of the sympathetic chain or in association with cranial nerves and blood vessels. http://repub.eur.nl/res/pub/25379/ 2009-11-01T00:00:00Z Context: Von Hippel-Lindau (VHL) disease, caused by germline mutations in the VHL gene, is a hereditary tumor syndrome manifested by hemangioblastomas, clear cell renal cell carcinomas, and pheochromocytomas. In addition, a multitude of other rare tumors, including parasympathetic paragangliomas, can occur and even be the sole manifestation of VHL disease. The VHL gene is a bona fide tumor suppressor gene with biallelic inactivation contributing to tumor formation. However, in parasympathetic paragangliomas occurring in VHL disease, biallelic inactivation of the VHL gene has not been demonstrated to date. Design: The head and neck paragangliomas of two VHL patients were analyzed for mutations by direct sequencing of the VHL gene. In addition loss of heterozygosity analysis was performed for three microsatellite loci near the VHL gene. To rule out other underlying genetic causes of the parasympathetic paragangliomas, mutation analysis of the SDHB, SDHC, and SDHD genes was also performed. Results: Apart from germline VHL mutations, no additional mutations were found in the paraganglioma-related tumor suppressor genes SDHB, SDHC, and SDHD. Analysis of paraganglioma tissue revealed loss of the VHL wild-type allele in both tumors, indicating that in these tumors biallelic VHL gene inactivation occurred. Conclusions: These findings indicate that parasympathetic paragangliomas in VHL disease, although rare, are part of the syndrome and related to VHL gene inactivation. Clinicians should be aware of the potential occurrence of parasympathetic paragangliomas in VHL disease. Copyright http://repub.eur.nl/res/pub/24539/ 2009-08-01T00:00:00Z Background: Phaeochromocytomas and paragangliomas are neuro-endocrine tumours that occur sporadically and in several hereditary tumour syndromes, including the phaeochromocytoma-paraganglioma syndrome. This syndrome is caused by germline mutations in succinate dehydrogenase B (SDHB), C (SDHC), or D (SDHD) genes. Clinically, the phaeochromocytoma-paraganglioma syndrome is often unrecognised, although 10-30% of apparently sporadic phaeochromocytomas and paragangliomas harbour germline SDH-gene mutations. Despite these figures, the screening of phaeochromocytomas and paragangliomas for mutations in the SDH genes to detect phaeochromocytoma-paraganglioma syndrome is rarely done because of time and financial constraints. We investigated whether SDHB immunohistochemistry could effectively discriminate between SDH-related and non-SDH-related phaeochromocytomas and paragangliomas in large retrospective and prospective tumour series. Methods: Immunohistochemistry for SDHB was done on 220 tumours. Two retrospective series of 175 phaeochromocytomas and paragangliomas with known germline mutation status for phaeochromocytoma-susceptibility or paraganglioma-susceptibility genes were investigated. Additionally, a prospective series of 45 phaeochromocytomas and paragangliomas was investigated for SDHB immunostaining followed by SDHB, SDHC, and SDHD mutation testing. Findings: SDHB protein expression was absent in all 102 phaeochromocytomas and paragangliomas with an SDHB, SDHC, or SDHD mutation, but was present in all 65 paraganglionic tumours related to multiple endocrine neoplasia type 2, von Hippel-Lindau disease, and neurofibromatosis type 1. 47 (89%) of the 53 phaeochromocytomas and paragangliomas with no syndromic germline mutation showed SDHB expression. The sensitivity and specificity of the SDHB immunohistochemistry to detect the presence of an SDH mutation in the prospective series were 100% (95% CI 87-100) and 84% (60-97), respectively. Interpretation: Phaeochromocytoma-paraganglioma syndrome can be diagnosed reliably by an immunohistochemical procedure. SDHB, SDHC, and SDHD germline mutation testing is indicated only in patients with SDHB-negative tumours. SDHB immunohistochemistry on phaeochromocytomas and paragangliomas could improve the diagnosis of phaeochromocytoma-paraganglioma syndrome. Funding: The Netherlands Organisation for Scientific Research, Dutch Cancer Society, Vanderes Foundation, Association pour la Recherche contre le Cancer, Institut National de la Santé et de la Recherche Médicale, and a PHRC grant COMETE 3 for the COMETE network.