Systemic treatment of a metastatic carotid body tumor: A case report and literature review.

RATIONALE Carotid body tumors (CBTs) are head and neck paragangliomas (PGLs) with a low incidence of distant metastasis. To date, only a few metastatic cases treated with detailed systemic therapy are reported and effective management is still inconclusive. Herein, we reported a metastatic CBT case with systemic therapy and reviewed the reported systemic treatment. PATIENT CONCERNS A 56-year-old man noticed multiple painless nodules on the right side of the neck and developed debilitating chest and back pain 7 years after the CBT resection. DIAGNOSES Widespread bone and lymph nodes CBT metastases. INTERVENTIONS Biopsies of the enlarged lymph nodes confirmed the diagnosis of metastatic CBT and 18F-FDG PET-CT detected multiple right cervical lymph nodes and bone metastases. 24 cycles of cyclophosphamide, vincristine and dacarbazine (CVD) chemotherapy were given since May 2016 to Jul 2018 and dacarbazine maintenance therapy was given in the next 15 months follow-up period. OUTCOMES Partial remission was achieved according to the Response Evaluation in Criteria in Solid Tumors 1.1 criteria. A prominent control in the metastatic lesions were also observed in 18F-FDG PET-CT scan. LESSONS Evidence for systemic management of metastatic CBTs is mainly based on studies of PGLs and pheochromocytoma. According to our review on metastatic CBT cases treated with systemic therapy from 1981 to 2018, chemotherapy, especially the CVD regimen, was a common reported management. In SDHB mutated patients, sunitinib and temozolomide could also be considered.