A rare case of huge paraganglioma in the parapharyngeal space is reported. A 57-year-old woman complained of dyspnea. CT scan and MRI showed an mass in the right parapharyngeal space, extending to the skull base. An angiogram of the right common carotid artery showed that the tumor had hypervascularity supplied by the external carotid artery and that the bifurcation of the carotid artery was widened. At surgery, the tumor was found to be firmly adherent to the right carotid bifurcation. Since it was impossible to dissect the tumor from the carotid artery, the internal and external carotid arteries were resected with the tumor after sufficient back-flow to the right internal carotid artery had been confirmed by preoperative angiography and no change of SSEP (somato-sensory evoked potential). Histopathologic examination confirmed a paraganglioma. Postoperatively, the patient exhibited no sign of hemiplegia but had paralyses of the right IX, X, XI and XII cranial nerves. The postoperative course wasp excellent, and close follow-up of the patient reveals no recurrence of the tumor.
Paragangliomas are uncommon tumors in the head and neck region. Intercarotid paragangliomas, which are relatively common among them, usually present with a painless mass in the neck. Our patient's paraganglioma appeared to be intercarotid from the findings of carotid angiograms and its adhesion to the carotid bifurcation. If the tumor must be resected with the internal carotid artery, back-flow to the internal carotid artery must be ascertained, and monitoring of the SSEP is indispensable.
