Differential Diagnosis and Treatment Outcomes of Tumors at the Carotid Bifurcation

Purpose: Primary tumor at the carotid bifurcation is uncommon, which includes paraganglioma, schwannoma, and lymphoma. Due to their rarity, characteristics of these tumors and problems related to their surgical treatment have not been well known. We tried to elucidate different clinical characteristics and surgical complications of these tumors. Materials and Methods: We retrospectively reviewed 21 patients with carotid bifurcation tumor from the Vascular Surgery division of a Korean tertiary institution from 1995 to 2018. We investigated patients' demographics and clinical features, image characteristics, treatment details, and surgical outcomes. Results: During the period from January 1995 to January 2018, we experienced surgical resections of 21 carotid bifurcation tumors which included 16 (76.2%) paragangliomas and 5 (23.8%) schwannomas. The most common clinical feature was a non-tender cervical mass. According to Shamblin classification, paragangliomas were classified into class II in 68.8% and class III in 25.0%. On the preoperative computed tomography images, all the paragangliomas showed characteristic splaying of the carotid bifurcation and hypervascularity of the tumors. On the contrary, all the schwannomas showed hypovascularity and splaying sign in 60%. Surgical complications related to cervical nerve injury developed in 50% and 60% of patients with Shamblin class III paraganglioma and schwannoma, respectively. During the mean follow-up period of 25 months (range, 1 to 163 months), distant metastases developed in 2 (12.5%) of paraganglioma patients. Conclusion: Neurologic complications were more common after surgical resection of Shamblin class III paraganglioma and schwannoma. For patients with paraganglioma, postoperative periodic follow-up examination is advised to detect distant metastasis.