Case Report: Carotid body paraganglioma in a 20-year-old woman: multimodal imaging, vessel-preserving surgical excision, and long-term clinical follow-up.

Carotid body paraganglioma is a rare hypervascular neuroendocrine tumor of the head and neck, and presentation in a 20-year-old woman is uncommon. We report a young woman with a painless left lateral neck mass present for more than 5 years, with more noticeable enlargement during the preceding year. On admission, a firm, mobile, non-tender mass was palpated along the anterior border of the left sternocleidomastoid muscle, without an audible bruit. Initial and targeted ultrasonography demonstrated a hypervascular lesion centered at the left carotid bifurcation. Preoperative contrast-enhanced computed tomography angiography (CTA) demonstrated a hypervascular mass centered at the left carotid bifurcation with widening of the bifurcation and separation of the internal and external carotid arteries; magnetic resonance imaging (MRI) showed a heterogeneously enhancing carotid-space mass with internal flow-void foci; and digital subtraction angiography (DSA) confirmed marked tumor blush, collectively supporting the diagnosis of carotid body paraganglioma. Surgical excision was performed under general anesthesia. Intraoperatively, the tumor crossed the carotid bifurcation, wrapped around the internal and external carotid arteries, and was extremely vascular; however, grossly complete, vessel-preserving excision was achieved with preservation of the carotid arteries, hypoglossal nerve, and vagus nerve. Histopathology confirmed carotid body paraganglioma with an organoid/nested architecture within a rich vascular stroma and immunohistochemistry showing synaptophysin (Syn)(+), chromogranin A (CgA)(+), S-100(+), and a Ki-67 labeling index of approximately 5%; the original pathology report did not specify a formal microscopic margin status. Balloon occlusion testing, biochemical catecholamine work-up, functional imaging, and genetic testing were not documented in the available record. The postoperative course was uneventful. Ultrasonographic follow-up on July 26, 2018 showed no definite recurrent lesion or obvious vascular abnormality, and long-term clinical follow-up by telephone revealed no recurrence-related symptoms, although no further imaging surveillance was available, and asymptomatic radiologic recurrence cannot be fully excluded. This case highlights the value of multimodal imaging in diagnosis and operative planning and shows that grossly complete, vessel-preserving excision can be associated with favorable short-term imaging and long-term symptom-based follow-up findings in a young patient.