Hartmut P.H. Neumann

Endoscopic treatment of large primary adrenal tumours.

Endoscopic adrenalectomy has become the treatment of choice for small benign adrenal tumours but should not be used for malignant lesions. It is debatable whether large and therefore potentially malignant primary adrenal tumours should be removed by minimally invasive techniques.

Mutations of the SDHB and SDHD genes.

The succinate dehydrogenase (SDH) is a mitochondrial enzyme complex with an important role in oxydative phosphorylation and intracellular oxygene sensing and signaling. Mutations in the SDHB (1p35–36) and SDHD subunits (11q23) give rise to the paraganglioma syndromes (PGL), namely PGL 4 and PGL 1, and generate paraganglioma and pheochromocytoma. For both genes mutations have been described that result in a loss of function of the gene products. SDHBmutations were found in five of eight exons and in two introns, SDHD mutations in all four exons and one intron. Phenotypes and rate of malignancy of SDHB and SDHD seem to be different, with a higher frequency of head-and-neck tumors in SDHD and indications of a higher risk of malignancy in SDHB mutations. As routine diagnostic procedure all SDH mutation carriers should have urine catecholamine analysis as well as pelvic, abdominal, thoracic and skull/neck MRI.

Genetic testing for pheochromocytoma-associated syndromes.

Pheochromocytoma and paraganglioma are tumors of the autonomic nervous system. Various syndromes have been found to be associated with the development of pheochromocytomas and paragangliomas: multiple endocrine neoplasia type 2 (MEN 2, susceptibility gene: RET), von Hippel-Lindau disease (VHL, susceptibility gene: VHL), neurofibromatosis 1 (NF 1), and paraganglioma syndromes type 1, 3, and 4 (susceptibility genes: succinate dehydrogenase gene, SDH, subunits D, C and B, respectively). Prevalence and clinical features of pheochromocytomas and paragangliomas are different for each of these syndromes. Mutational analysis of the susceptibility genes of these syndromes in patients presenting with pheochromocytoma or paraganglioma may help to judge the risks of multifocality of the tumor as well as development of malignant pheochromocytoma or of other malignant tumors. Here we review the recent progress in clinical characterization and genetic testing for these syndromes. Based on tumor characteristics and prevalence data we give recommendations for an efficient genetic testing procedure in patients presenting with pheochromocytomas and paragangliomas.

Von Hippel-Lindau disease: a rare disease important to recognize

Introduction: Von Hippel-Lindau disease (VHL) is an autosomal dominant multisystemic cancer syndrome due to a mutation of the VHL tumor suppressor gene on chromosome 3, region p25-26, with an incidence of 1/36,000 in newborns. Patients are at risk of developing cerebellar, spinal and retinal hemangioblastoma, renal cell carcinoma, pheochromocytoma, pancreatic neuroendocrine tumors, pancreatic and renal cysts, and epididymal cystadenoma. The most common causes of death from VHL are metastases from renal cell carcinoma and neurological complications from cerebellar hemangioblastomas. Molecular analysis of the VHL gene is clinically available and indicated in patients with known or suspected VHL. Case Report: A 19-year-old woman was surgically treated for cerebellar hemangioblastoma in 1998 and for renal cell carcinoma of the right side in 2002. Familial VHL was subsequently diagnosed as the patient’s mother was found to be affected with bilateral polycystic kidney disease with chronic renal failure as well as hemangioblastoma of the retina and medulla oblongata. The mother underwent surgery for bilateral renal cell carcinoma in 2003. Conclusion: The multitude of VHL-associated tumors and intra-familial variability in clinical expressivity render early diagnosis of VHL difficult. We therefore shortly illustrate the spectrum of clinical phenotypes and the VHL screening and surveillance guidelines.

Paragangliomas in patients with mutations of the SDHD gene

OBJECTIVE: Paragangliomas represent neoplasms of neural crest origin that arise from paraganglia. Mutations in the gene encoding succinate dehydrogenase subunit D (SDHD) are responsible for a percentage of hereditary paragangliomas. We previously described a group of 271 pheochromocytoma patients, 11 of whom had mutations of the SDHD gene. The objective of this study was to find out whether those 11 patients had additional paragangliomas. STUDY DESIGN: Ten patients participated in our clinical screening program that included MRI of the skull base and neck, thorax, and abdomen, as well as an 18Fluoro-DOPA positron emission tomography (DOPA-PET). RESULTS: Five patients presented with head and neck paragangliomas, 1 patient with a thoracic paraganglioma, and 2 patients with intraabdominal paragangliomas. CONCLUSIONS: The screening for paragangliomas in patients with mutations of the SDHD gene offers the chance to diagnose those tumors in an early stage. SIGNIFICANCE: Because morbidity after surgical resection increases with tumor size, early surgery will minimize the potential risks.