Foreword

Paragangliomas and pheochromocytomas are rare tumors of the autonomic nervous system that pose important clinical questions. Their presentation may be extremely variable. Classic sites of origin, such as the adrenal medulla and the autonomic branches of the lower cranial nerves, are the most frequent locations, but other sites may also be involved. Paragangliomas may indeed arise in connection with autonomic neural branches almost anywhere in the thoracic, abdominal, and head and neck regions. Some of these locations are accessible only by surgeons with special skills, not easy to acquire, given the rarity of the disease in general and of the specific locations, in particular.

Early diagnosis may be problematic, particularly when patients are seen by physicians who do not have specific experience. This may have relevant consequences, as surgical resection, which must be radical, is still the mainstay therapy, and late diagnosis may complicate surgery. In fact, paragangliomas, despite their slow growth, in most cases they do not grow more than few a millimeters in diameter per year, tend to relentlessly infiltrate adjacent anatomical structures, most often extending along regional neurovascular bundles. With time, this behavior makes their resection difficult and, in some instances, even impossible. Such is often the case for those paragangliomas that, arising at the skull base, extend within the skull, either through neurovascular foramina or by direct bone erosion. Another challenge is represented by the possible secretion of catecholamines, more frequent in pheochromocytomas and sympathetic thoracoabdominal paragangliomas. This may per se entail life-threatening cardiovascular complications. Such tumors require cautious surgical approaches and well-trained multidisciplinary surgical teams. Read more...