[Head and neck paragangliomas: An interdisciplinary challenge]

Rare Diseases of the Oral Cavity, Neck, and Pharynx

Diseases occurring with an incidence of less than 1-10 cases per 10 000 individuals are considered as rare. Currently, between 5 000 and 8 000 rare or orphan diseases are known, every year about 250 rare diseases are newly described. Many of those pathologies concern the head and neck area. In many cases, a long time is required to diagnose an orphan disease. The lives of patients who are affected by those diseases are often determined by medical consultations and inpatient stays. Most orphan diseases are of genetic origin and cannot be cured despite medical progress. However, during the last years, the perception of and the knowledge about rare diseases has increased also due to the fact that publicly available databases have been created and self-help groups have been established which foster the autonomy of affected people. Only recently, innovative technical progress in the field of biogenetics allows individually characterizing the genetic origin of rare diseases in single patients. Based on this, it should be possible in the near future to elaborate tailored treatment concepts for patients suffering from rare diseases in the sense of translational and personalized medicine. This article deals with orphan diseases of the lip, oral cavity, pharynx, and cervical soft tissues depicting these developments. The readers will be provided with a compact overview about selected diseases of these anatomical regions. References to further information for medical staff and affected patients support deeper knowledge and lead to the current state of knowledge in this highly dynamic field.

[Surgical treatment options for cervical paragangliomas]

The therapies available for the rare tumor entity of cervical paraganglioma (PG) are currently undergoing a paradigm shift. The treatment of choice for small carotid body tumors, malignant and active endocrine tumors is surgical resection; however, for locally advanced carotid body tumors and vagal PG, surgical therapy should be critically evaluated. Due to the immediate proximity of these hypervascularized tumors to the caudal cranial nerves, there is a risk of severe nerve damage with a significant impairment of quality of life after resection, particularly for locally advanced cervical PG, emphasizing further the importance of a restrictive surgical strategy. External radiotherapy can provide an equivalent primary therapeutic option with respect to the rate of recurrence and is accompanied by a lower morbidity. The slow rate of tumor progression and the multifocality of the familial variant of cervical PG or significant comorbidities in older, asymptomatic patients warrant a less aggressive treatment strategy for these tumors. When a wait and scan approach is implemented, a closely monitored radiological and clinical re-evaluation is of upmost importance. In a multidisciplinary approach the following critical points require consideration before a therapy is implemented,: size and location of the tumor, progression rate, genetic background, patient age and general condition, relevant comorbidities, the presence of synchronous PG and/or vasoactive catecholamine-producing tumors. Although best practice algorithms for the treatment of cervical PG have already been devised, recent innovative developments have led to more patient-tailored, individualized treatment approaches.

[Interventional radiology in the head and neck region]

In interventional neuroradiology, endovascular embolization represents an important and helpful tool in the treatment of multiple head and neck diseases. These interventional procedures may be performed with curative intent, to reduce the surgical risk within a multimodal treatment concept, or to improve or at least maintain a good quality of life within a palliative therapy concept. In addition to a good understanding of disease pathology, knowledge of vascular anatomy, including collateral vessels and dangerous extracranial-intracranial anastomoses, is essential for successful treatment, as is implementation of an established technique using appropriate material. Indications for endovascular embolization are i. otherwise unmanageable bleeding (caused by e. g., trauma, vascular malformation, or tumor), ii. reduction of perioperative bleeding by preoperative embolization in case of a hypervascularized tumor, iii. selective induction of tumor necrosis by palliative embolization to enhance local tumor control. Major complications such as stroke, loss of vision, and cranial nerve palsy are mostly due to a lack of preinterventional evaluation. Regarding neurological deficits, interventions within the supply region of the external carotid artery have a complication rate below 1%.

[Percutaneous embolization and ultrasound scissors for removal of a carotid body tumor]

Paragangliomas are highly vascularized usually benign neoplasms originating from the sympathoadrenal and parasympathetic paraganglia of the autonomic nervous system. When resectable, the management of these tumors consists of surgical ablation preceded by transarterial embolization. The aim of this article is to describe a novel treatment strategy combining intralesional percutaneous embolization with dissection using ultrasound scissors. The case of a 74-year-old women presenting with a Shamblin type III carotid body paraganglioma is presented. The combined approach of percutaneous embolization and ultrasound scissors permitted complete resection of the tumor with preservation of both the internal and external carotid artery, without postoperative cranial nerve deficits and with minimal blood loss. Preoperative intralesional embolization with a liquid embolic agent less than 24 h prior to surgical intervention in combination with ultrasound scissors appears to be an excellent strategy for surgical management of carotid body paragangliomas.