http://repub.eur.nl/res/aut/31144/ List of Publications en http://repub.eur.nl/static-eur/img/logo.png http://repub.eur.nl 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. http://repub.eur.nl/res/pub/35302/ 2007-08-01T00:00:00Z The current clinical diagnosis of Von Hippel-Lindau (VHL) disease demands at least one specific a sporadic VHL manifestation in a patient with familial VHL disease, or, in asporadic patient, at least two or more hemangioblastomas or a single hemangioblastoma in combination with a typical visceral lesion. To evaluate this definition, we studied the frequency of germline VHL mutation in three patients groups: (i) multi-organ involvement (classic VHL), (ii) limited VHL manifestations meeting criteria (non-classic VHL) and (iii) patients with VHL-associated tumors not meeting current diagnostic VHL criteria. In addition, we validated multiplex ligation-dependent probe amplification (MLPA) as a rapid and reliable quantitative method for the identification of germline VHL deletions. The frequency of germline VHL mutations was very high in classic VHL cases with multi-organ involvement (95%), lower in non-classic cases that meet current diagnostic criteria but have limited VHL manifestations or single-organ involvement (24%) and low (3.3%), but tangible in cases not meeting current diagnostic VHL criteria. The detection of germline VHL mutations in patients or families with limited VHL manifestations, or single-organ involvement is relevant for follow-up of probands and early identification of at-risk relatives. http://repub.eur.nl/res/pub/35309/ 2007-07-19T00:00:00Z http://repub.eur.nl/res/pub/36121/ 2007-03-01T00:00:00Z Objective: Pheochromocytomas are uncommon tumours arising from chromaffin cells of the adrenal medulla and related paraganglia. So far, one of the few reported markers to discriminate malignant from benign tumours is the βB-subunit of inhibin and activin, members of the transforming growth factor (TGF)-β superfamily of growth and differentiation factors. Design: We investigated the expression of the mRNAs coding for activin and inhibin subunits, their receptors and binding proteins by quantitative reverse transcriptase-polymerase chain reaction (RT-PCR) and studied the presence of the inhibin βB-subunit in human pheochromocytomas by immunohistochemistry. Patients: Samples from resected pheochromocytomas of patients operated between 1973 and 2003 were used for experiments. Results: The immunohistochemical investigations revealed that staining of the inhibin βB-subunit was positive in 12 of 36 (33%) benign and 5 of 34 (15%) malignant pheochromocytomas (P > 0.05). Therefore, it was not possible to discriminate between benign and malignant tumours solely on the basis of inhibin βB-subunit immunohistochemistry. Quantitative real-time RT-PCR in nine benign and four malignant tumours showed expression of inhibin α-, βA- and βB-subunits, the activin receptors Alk-4, ActRIIA, and ActRIIB, and the inhibin- and activin-binding proteins betaglycan and follistatin in all samples. No correlations were detected between individually coupled expression of mRNAs of these activin- and inhibin-related genes in the 13 pheochromocytomas. Only inhibin βA-subunit expression was different in malignant compared to benign pheochromocytomas (P = 0.020). Conclusions: No clear role for activin and inhibin was found in discriminating between benign and malignant pheochromocytomas.