Carotid body tumors are relatively rare. In 1743, Von Haller first noted the carotid body and considered it a small gland. In 1891, Marchand reported a case of carotid body tumor and performed surgical treatment, but the patient died three days after the operation. By 1969, more than 500 cases of carotid body tumors had been reported. The carotid body is mostly located at the bifurcation of the common carotid artery, encapsulated, with variable size, approximately 3.5 mm in diameter, and rich in blood vessels and nerves. Its blood supply comes from small branches of the common carotid artery, and its nerves originate from the cervical sympathetic ganglia, glossopharyngeal nerve, vagus nerve, and hypoglossal nerve. Grossly, carotid body tumors appear reddish-brown, round or oval, lobulated, and encapsulated. The cells are mainly polygonal, with eosinophilic cytoplasm containing numerous vacuoles and microsomes. These tumors commonly occur in individuals aged 30 to 40, with a malignant transformation rate of 5–10%.

bubble_chart Clinical Manifestations

As the tumor grows and expands in different directions, various symptoms may occur. Small, slow-growing tumors often have no symptoms or may cause pain and a sense of pressure. Larger tumors compressing nerves may lead to symptoms such as syncope, hoarseness, dysphagia, and dyspnea. Physical examination: the tumor is usually unilateral, located at the bifurcation of the common carotid artery in the carotid triangle, deep to the sternocleidomastoid muscle, without adhesion. The tumor is round or oval, rich in blood vessels, and may expand and contract or produce murmurs and tremors. Since the tumor is attached to the carotid artery, it can often move side to side but not up and down.

It is often difficult to differentiate carotid body tumors from other benign tumors before surgery, and diagnosis usually relies on auxiliary examinations, intraoperative findings, and postoperative pathological diagnosis. Carotid body tumors are mostly located at the bifurcation of the common carotid artery, and pressing the mass often causes the artery to move along with it. B-ultrasound and CT scans may reveal a high-density shadow at the carotid artery bifurcation. Digital subtraction angiography can visualize the artery, and if the tumor has large feeding branches, the mass may also be visualized.

bubble_chart Treatment Measures

The primary treatment is surgery. Due to the slow growth of this tumor and the high risks associated with surgery, smaller tumors may be monitored with follow-up observation. However, as the tumor enlarges, it increases surgical difficulty and mortality. Carotid body tumors are not sensitive to radiotherapy, which may shrink the tumor but also raises the risk of malignant transformation and complicates tumor separation during surgery. The main challenges of surgical treatment include carotid artery injury, hemorrhage, and cranial nerve injury. Preoperative considerations should address the potential need for common carotid artery ligation, with intermittent compression of the affected side to enhance cerebral tolerance. Selective angiography may reveal vascular supply to the tumor from branches of the external carotid artery and newly formed vessels. Embolization of the carotid artery branches supplying the tumor using ethanol-polyvinyl particles can reduce intraoperative bleeding. Most tumors can be dissected from the common or internal carotid artery, and the external carotid artery should be ligated while minimizing injury to cranial nerves IX, X, XI, and XII. Injuries to the common or internal carotid artery may be managed by ligation or reconstruction, with a mortality rate of 30–50% for common carotid artery ligation.

Attention should be paid to differentiate it from cervical lymphadenopathy, branchial cleft cyst, lymphoma, neurofibroma, and other conditions.