Paragangliomas or chemodectomas are according to their origin classified as neuroectodermal tumours. As to their basis and structure they are near to ganglioneuromas which is differentiated near to the structure of the adrenal medulla. In the ENT area, contrary to classical pheochromocytoma, we encounter the achromaffine extraadrenal variant which develops from tissue of sympathetic and parasympathetic ganglia. In the area of head and neck evidence of pressor substances produced by tumours is rare in the same may as malignant variants of these tumours. Macroscopically glomus tumours can be characterized as encapsulated, lobular, redish to violet coloured formations depending on the vascularization of the tumour. Microscopically similarly as in paraganglia there are two types of cells, the main (eptheloid) - type I and sustentacular - type II. The basic structural unit is a defined agglomeration of main cells which is called Zellballen. The extraadrenal variant of the tumour is characterized in addition to inadequate argentaffinity by a good and sharply defined separation of alveolar tumourous foci connective tissue strips with wide sinusoid capillaries. Only rarely it is possible to observe a periteliomatous pattern. In the microscopic structure of these tumours participates the axial ending of a nonmyelinized nerve immersed into cells of the Schwann type. When investigating the incidence of glomus tumours within the framework of genealogical studies a certain hereditary relationship was found whereby the prob- able transfer between different generations is autosomally dominant. There is also an increased predisposition of the incidence of paragangliomas in women and an increased incidence (up to 50%) of multiple incidence of tumours in different affected members of the family, while in patients without a family load of the basic disease the multifocal incidence is slightly lower, ca by 10%. The authors observed also a tendency of the multiple incidence of these tumours in conjunction with advancing age of the patients and a tendency of a possibly higher incidence of paragangliomas in children of affected men. Genetic predisposition of familial glomus depends on one allele. The most frequent familial type of chemodectoma is the glomus caroticum tumour (up to 80%). A typical manifestation of paragangliomas is slow progression of growth. The first clinical signs of these neoplasias are usually observed several years after development of the tumour. Only about 3% of these cases can be considered malignant, in particular because of metastases. These tumours are known by their very slow locoregional spread. The authors present a group of patients examined and treated at a clinical ENT department in the course of 10 years on account of the diagnosis of paraganglioma. The group comprises a total of 15 patients, incl. 11 women (73.3%) and 4 men (20.7%). The average age of the operated patients was 37.5 years, range 20 tp 73 years. As to sites, tympanojugular chemodectomas were found in 33.3%, a glomus vagale tumour in five instances (26.7%), a paraganglioma of the carotid sinus was proved in five instances (33.3%) and in one case the finding was described as a metastasis of a paraganglioma which was originally in the aortic arch and which was already previously treated at a surgical department. In two patients (13.3%) anamnestically multiple incidence of paragangliomas was described incl. one female patient who was treated previously at another department on account of chemodectoma at another site, primarily by radiotherapy with two relapses in this area which were subsequently treated by a combination of surgery embolization and radiotherapy. In another patient in the past repeatedly surgery was used at the same site for of chemodectoma, in another department. However ther was multicentric incidence, i.e. first a glomus vagale tumour and later a carotid paraganglioma which was confirmed on operation and histological examination. The preoperative diagnosis of glomus tumours was based on a detailed case-history, clinical picture and imaging methods. In the cervical region ultrasonography was used, digital subtraction angiography twice supplemented by CT examination. In the area of the cranial base always digital subtraction angiography was used supplemented by CT or possibly MR examination. In three patients with suspected endocrine activity catecholamine breakdown products were examined in urine and in one case raised levels were found in a female patient with netastases of an aortal paraganglioma in the cervical region. All patients were treated primarily by radical removal of the tumour. After surgery in none of the patients actinotherapy was indicated nor treatment with Leksell’s gammaknife. In conjunction with surgery no inflammatory complications were observed in the area of the operational field. Postoperative clinical complications involved discontinuation of anatomical structures which the tumour infiltrated and which had to be removed to achieve a primary radical operation. The follow-up in the investigated patients is on average 2.8 years with a range of 7 months to 10 years and during the follow-up period no relapse of the basic disease was observed in conjunction with the administered treatment.

        Key words: paragangliomas, surgical treatment, complications, Leksell’s gammaknife, actinotherapy.