Carotid body paraganglioma metastatic to spine causing cord compression: a case report

Abstract

Background: Carotid body tumors (CBTs) are rare neuroendocrine neoplasms arising near the carotid bifurcation with a reported incidence of 1 to 2 cases in 100,000 patients. Most CBTs are sporadic, benign, slow-growing, and non-secreting, but untreated CBTs can grow locally to compress the nearby blood vessels, esophagus, and airway. Regional metastases can occur in 5% to 10% of cases, but distant metastases are exceedingly rare, occurring in roughly 1-2% of cases. As such, the optimal treatment for metastatic CBTs is not well-defined. We report a rare case of a patient with CBT distant metastases causing spinal cord compression.

Case presentation: A 40-year-old African American female presented with a right neck mass, headaches, vertigo, tinnitus, hoarseness, and dysphagia. Imaging demonstrated a Shamblin II right neck mass; subsequent transcervical resection and pathology showed a carotid body paraganglioma. The patient recurred locally near the carotid bifurcation, so she underwent Stereotactic Body Radiation Therapy to the recurrent right neck disease. She later re-presented with new onset bilateral lower extremity weakness, dysmetria, and numbness. She was found to have metastatic disease to the thoracic spine causing spinal cord compression. She underwent laminectomy, tumor resection, and posterior fixation followed by adjuvant radiation therapy. She was started on systemic therapy with sunitinib. She eventually progressed with metastatic disease to the right iliac bone, which was treated with palliative radiotherapy. Second line systemic therapy with capecitabine and temozolomide was started. At last follow up, the patient was asymptomatic with stable persistent disease.

Conclusions: Paragangliomas often exhibit a prolonged interval to the development of progression; locoregional recurrences or rare distant metastases have been reported to occur as many as 20 years from diagnosis. The natural course of CBTs in other cases as well as the present case call into question the idea that CBTs are truly benign; instead CBTs may be indolent tumors with metastatic potential. Treatment choices for CBTs include surgical resection, radiation therapy, and systemic therapy, though the optimal treatment regimen for metastatic CBTs is not well-defined. A more advanced understanding of CBT pathophysiology, disease classification, risk stratification, and treatment options is needed to improve outcomes for patients.

Keywords: Carotid body tumor; Cord compression; Metastatic; Paraganglioma; Radiotherapy.

Fig. 1

A shows an axial CT neck with contrast. There is a 6.1 × 4.0 × 4.1 cm contrast-enhancing right neck mass in the right carotid space centered at C3. The mass partially surrounds the external and internal carotid arteries consistent with a Shamblin group 2 lesion. B and C show a T2 weighted MR thoracic spine using Fast Recovery Fast Spin Echo (FRFSE). B depicts a sagittal view where the arrow indicates posterior to anterior spinal cord compression at the level of T7. There is a sharply circumscribed lesion in the right posterolateral aspect of the T11 vertebral body. C depicts an axial view with an expansile mass in the left posterolateral vertebral body, pedicle, laminae, and transverse process of T7. The T7 lesion expands the left posterior epidural compartment compressing the spinal cord anterolaterally towards the right. The arrow points to a small amount of visible cerebrospinal fluid indicating Bilsky grade 2 cord compression

Fig. 2

Hematoxylin and eosin staining of the resected thoracic spine tumor shows metastatic paraganglioma characterized by neuroendocrine cells which occupy the marrow spaces of cancellous bone. The semicircular, hematoxylinophilic curved structure at left represents one of the distorted, calcific bone trabeculae. Occasional foci of hemosiderin are present, consistent with chronic hemorrhage. Immunohistochemical stains of the tumor cells are strongly positive for both synaptophysin and chromogranin, and negative for pancytokeratin and Cam5.2. The Ki-67 proliferation index is elevated at about 20%. The staining pattern is consistent with paraganglioma