Extracranial bone metastases from recurrent anaplastic astrocytoma on FDG PET/CT

Abstract

Objective:Extracranial bone metastases from astrocytoma are rare and frequently detected as part of multiorgan metastases. It is extremely rare for astrocytoma to have extracranial bone metastases alone. The importance of whole-body fluorodeoxyglucose positron emission tomography/computed tomography (FDG PET/CT) imaging in evaluating extracranial metastasis (ECMs) has not been described effectively due to the rarity of this event. The purpose of our case report is to emphasize the role of FDG PET/CT in the assessment of tumor recurrence and extracranial bone metastases from anaplastic astrocytoma.Methods and materials:A 25-year-old woman was firstly admitted with a 4-month history of progressive blurred vision, and 2-month history of intermittent headache. Presurgical MRI imaging revealed a large mass in the left trigone of lateral ventricle. Subsequently, she underwent tumor resection, radiotherapy and chemotherapy. A final pathological diagnosis of anaplastic astrocytoma (WHO III) was made. Nearly 12 months after the surgery, the follow-up brain MR imaging revealed a contrast-enhanced lesion in the site of operative region. Whole-body FDG PET/CT imaging was performed to evaluate the situation.Results:Postoperative brain FDG PET/CT showed an abnormal focal FDG uptake corresponding to the contrast-enhanced lesion in the operative area, suggesting a tumor recurrence. Whole-body FDG PET/CT also showed multiple FDG-avid osteosclerotic lesions in the body. It was highly suggestive of extracranial bone metastases. A subsequent open bone biopsy of FDG-avid lesion in right iliac crest was performed. Histopathological and immunohistochemical findings indicated characteristic of glioma. The patient died 1 month later, nearly 13 months after the initial diagnosis.Conclusions:ECMs from anaplastic astrocytoma are extremely rare but they do occur. Whole-body FDG PET/CT imaging with inclusion of brain was valuable in differentiating tumor recurrence from radiation necrosis and in detecting uncommon extracranial bone metastases from anaplastic astrocytoma, which were closely related to prognosis of this disease.

Unusual Extra-Axial and Extracranial Recurrence in an IDH Mutant Astrocytoma: A Case Report

“…Common sites include the lymph nodes, bone, soft tissue, skin, and liver. 22 23 In skeletal metastases, vertebral bodies are most commonly involved, 24 likely through seeding from the Bateson plexus. 24 Spread via breakdown of the blood–brain barrier via tumoral vessels or invasion of dural veins, lymphogenous, and hematogenous spread by direct extracranial bone and soft tissue infiltration, through the CSF, by ventricular shunting are proposed mechanisms.…”

Extracranial metastasis of anaplastic oligoastrocytoma

“…Whole body imaging can be performed by positron emission tomography/computed tomography (PET/CT), which can identify abnormal, highly metabolic lesions and exclude potentially undiagnosed primary tumors. Therefore, the extensive application of whole body PET/CT imaging can replace complete autopsy as new ECM diagnostic criteria 8 . Nevertheless, the final pathologic biopsy remains the most accurate diagnostic method for ECM of glioma.…”

Whole-body 18F-Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography Demonstrating Multiple Rare Extracranial Metastases in a Treated Case of Glioblastoma

“…However, the report of 18 F-FDG PET/CT imaging in evaluating ECM is limited, and the importance of whole-body 18 F-FDG PET/CT imaging in ECM has not been well elucidated. [ 6 , 7 ] Mirzayan et al . reported the usefulness of whole-body 18 F-FDG PET/CT in detecting ECM in GBM.…”