18F-FDG PET/CT imaging for aggressive melanotic schwannoma of the L3 spinal root

摘要

RATIONALE:Melanotic schwannoma (MS) is an unusual variant of a nerve sheath neoplasm that accounts for less than 1% of all primary peripheral nerve sheath tumors. Fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) has unique value in detecting malignant MS lesions. To date, only 4 cases of MS with hepatic metastasis have been reported. Herein, we report the fifth case, which is the first reported patient with MS of Asian ethnicity with hepatic metastasis.PATIENT CONCERNS:A 29-year-old woman with a 1-day history of backache was admitted to our hospital. PET/CT showed a paravertebral heterogeneous soft tissue mass along the spinal nerve at the L2-L3 level with strong FDG uptake, and a nodule with increased FDG uptake in the lateral lobe of the left liver.DIAGNOSIS:A puncture biopsy of the L3 bony destruction and surrounding soft tissue mass was performed. The final diagnosis was spinal MS with hepatic metastasis.INTERVENTIONS:The patient underwent 6 courses of systemic chemotherapy.OUTCOMES:The patient did not receive further treatment for half a year after the end of chemotherapy and recovered well.LESSONS:Unlike conventional schwannomas, which are completely benign, MS has an unpredictable prognosis. It is thought to have low malignant potential, and the malignant type tends to metastasize. FDG PET/CT has a unique and important value in the differential diagnosis of benign and malignant lesions, in detecting occult metastases, monitoring the treatment response, and assessing the prognosis of MS.Copyright ? 2021 the Author(s). Published by Wolters Kluwer Health, Inc.