RESUMEN
Objective: To analyze the distribution and radiological findings of paragangliomas of the head and neck region at Siriraj Hospital. Methods: The cases with pathological proven of paragangliomas in the head and neck from January 1996 to December 2003 at Siriraj Hospital were retrospectively reviewed. Clinical presentation and radiologic findings in term of location, size, number, pattern of enhancement, vascularity and bony destruction were analyzed. Results: There were 26 tumors among 22 patients which were 12 females and 10 males, with an average age of 47 years old. By locations, paragangliomas were found as carotid body tumor in 46.2%, glomus tympanicum in 11.5%, glomus vagale in 11.5%, glomus jugulare in 3.8%, glomus jugulotympanicum in 7.6% and rare locations in 19.2%. The unusual locations included sinonasal cavity, sphenoid sinus, supraglottic larynx, thyroid gland and posterior fossa. The presenting symptoms were neck mass in 53.8%, tinnitus in 26.9%, cranial nerve palsy in 19.2%, epistaxis in 3.8%, hoarseness of voice in 3.8%, severe headache in 3.8%. Multicentricity was found in 18%. Aggressive pattern was documented in 15.4 %. The radiological findings of paragangliomas in usual locations were all characteristic homogeneous intensely enhanacement or hypervascularity (100%). Those in rare locations had also central necrosis (60%). Bony destruction was shown in 9.5% of usual locations and 40% of unusual locations. No any of lesions in rare locations had multicentricity. Conclusion: Carotid body tumor is the most common paragangliomas in the head and neck region. Clinical presentation of a paraganglioma is related to location of the tumor. On the basis of the locations and radiographic characteristics, in common locations, imaging findings are characteristics and they may provide definite diagnosis, but in rare locations the radiological findings are not characteristics, and should be differentiating from other head and neck lesions.