ABSTRACT
BACKGROUND: Schwannoma is a rare benign tumor derived from nerve sheaths. When derived from the cervical sympathetic chain, it usually presents itself as an asymptomatic mass located in the posterior cervical region, at paravertebral level. Its diagnosis is not easy, usually requiring multiple imaging tests. Its differential diagnosis includes parathyroid adenoma. CLINICAL CASE: A new case of schwannoma of the cervical sympathetic chain in a patient with a synchronous overactive parathyroid adenoma is reported. This case adds to the sixty described in the literature, although to our knowledge no association between schwannoma and parathyroid adenoma has been reported to date. CONCLUSIONS: Despite being a benign tumor, its treatment is a complete surgical resection. The most common complication after the surgery needed for these tumors is ipsilateral Horner syndrome.