Clinicopathological characteristics of patients with carotid body tumor with cervical lymph node metastasis: A retrospective study of 10 cases and review of the literature.

Carotid body tumor (CBT), also known as carotid body chemoreceptor tumor or nonchromaffin paraganglioma, originates from the chemoreceptor behind the common carotid artery bifurcation in the carotid sheath. Most CBTs are benign. Malignant CBT (MCBT) is extremely rare, and cervical lymph node metastasis (CLNM) is usually regarded as a manifestation of malignant behavior. The association between CLNM, pathological features of the primary lesion, clinical manifestations, and prognosis deserves further investigation. The clinical materials of 133 patients with CBT who underwent total resection of the primary tumor and concomitant selective neck dissection (SND) from February 2002 to June 2018 in a single center were reviewed. Postoperative histopathology confirmed CLNM in 10 cases (10/133); clinical manifestations, pathological and imaging characteristics, and treatment outcome data were reviewed and analyzed. The average patient age was 50.5 years, with a female sex tendency (7/10). The mean and median follow-up periods of all cases were 6.9 years and 7 years, respectively. Nine patients (9/10) survived; one patient died of multiple systemic metastases 10 months after surgery when the tumor metastasized to the bilateral breast and other organs in an orderly manner. None of the patients had local recurrence, but postoperative residual lesions were detected by computer-aided 3-dimensional (3D) visualization computerized tomography in one (1/10). Most CBT cases with CLNM displayed adverse features, especially in patients without distant metastases. Immunohistochemically, the patient with distant metastases was negative for S-100, synaptophysin (Syn), and succinate dehydrogenase B (SDHB) expression. Most patients with CBT with CLNM have a good prognosis. Breast metastasis is an exceedingly rare manifestation of MCBT. Despite some association between clinical biological and histological malignancies in CBT with CLNM, the association seems to be vague in cases involving distant metastasis. The combination of certain immunohistochemical indicators (S-100, Syn, and SDHB) might be valuable for predicting the occurrence of distant metastasis. Computer-aided 3D visualization technology might be helpful for the diagnosis and postoperative follow-up of MCBT. Simultaneous SND can remove potentially metastatic lymph nodes and facilitate diagnosis and treatment.