FDG PET/CT in Recurrent Glioblastoma Multiforme With Leptomeningeal and Diffuse Spinal Cord Metastasis

Disappearance of "Elongated Pony Tail Sign" Following Chemoradiotherapy in a Case of Primary Cerebellopontine Angle Ependymoma With Spinal Drop Metastasis: 18 F-FDG PET/CT Scan Findings

ABSTRACT

Ependymomas are rare glial tumors that commonly arise from the lining cells of ventricular system and constitute ~10% of intracranial pediatric malignancies. The incidence of ependymoma in adults is rare. Due to close approximation with the ventricular system, subtentorial ependymomas are more prone to show cerebrospinal fluid metastasis compared with supratentorial ependymomas. We present a case of subtentorial cerebellopontine angle ependymoma with diffuse spinal drop metastases showing "elongated pony tail appearance" in a 69-year-old man with complete metabolic response on 18 F-FDG PET/CT imaging following chemoradiotherapy.

Granulomatosis With Polyangiitis of Spinal Dura Presenting With "Bottle Brush Sign" on 18 F-FDG PET/CT

ABSTRACT

A 72-year-old man with fever and weakness in both lower limbs underwent thoracolumbar MRI and 18 F-FDG PET/CT. The PET/CT scan revealed diffused FDG uptake along the spinal dura mater from T7 to S2 level like a "bottle brush." Pathologic examination after biopsy of spinal canal lesions manifested granulomatous inflammation. The blood test showed cytoplasmic antineutrophil cytoplasmic antibody (ANCA) and myeloperoxidase-ANCAs were positive, whereas the perinuclear ANCA was negative. Eventually, he was diagnosed with granulomatosis with polyangiitis.

Solitary Dural Metastasis From Neuroblastoma Detected by 123 I-MIBG SPECT/CT

ABSTRACT

123 I-MIBG SPECT/CT was performed for follow-up in an asymptomatic 8-year-old girl with a history of neuroblastoma. The images showed an unsuspected abnormal accumulation in the head, which was identified as a hyperdense lesion of the dura with increasing MIBG uptake, suggesting the possibility of metastasis from neuroblastoma. A brain MRI with contrast showed a remarkably enhanced lesion beside the confluence of sinuses, which mimicked meningioma. Results of the surgical pathology are consistent with the diagnosis of dural metastasis from neuroblastoma.

Leptomeningeal Metastasis From Neuroblastoma Revealed by 123 I-MIBG SPECT/CT

ABSTRACT

A 2-year-old girl with history of high-risk neuroblastoma underwent 123 I-MIBG, which showed increased 123 I-MIBG in the left side of the head. Contrast-enhanced MRI and cerebral spine fluid cytology confirmed the diagnosis of leptomeningeal metastasis.

18 F-FDG PET/CT Findings of Leptomeningeal Metastasis in Nasopharyngeal Carcinoma

ABSTRACT

Nasopharyngeal carcinoma (NC) is an epithelial tumor with distinctive prevalence in East and Southeast Asia. Most patients with NC only experience regional metastasis. In cases of distant metastasis, prognosis is grim. Leptomeningeal spread of the disease is a rare occurrence, which is sparsely described in the literature. We present a case of a 33-year-old man with a history of high-grade NC with leptomeningeal metastasis. Initial MRI lumbar spine demonstrated subtle findings consistent with leptomeningeal disease. These findings are easily discernible on 18 F-FDG PET/CT.

Glioblastoma, IDH-wildtype with leptomeningeal metastasis to Meckel's cave: A case report

Meckel’s cave or the trigeminal cistern is a subarachnoid space near the apex of the petrous portion of the temporal bone and contains cerebrospinal fluid and the Gasserian ganglion, which divides into the ophthalmic (V1), maxillary (V2), and mandibular (V3) nerves. Infectious, inflammatory, congenital, and neoplastic lesions can occur in Meckel’s cave. Leptomeningeal metastasis of glioblastoma (GBM), IDH-wildtype to Meckel’s cave is rare. We encountered a case of leptomeningeal metastasis of GBM to Meckel’s cave in an elderly female patient who presented with pain around her right eye. Magnetic resonance imaging revealed enhancing lesions in the right temporal lobe and cervical spinal cord. The pathological diagnosis of GBM was confirmed after biopsy of the cervical spinal cord lesion, which showed hyperaccumulation of fluorodeoxyglucose (FDG) on FDG-positron emission tomography. This case indicates that metastatic lesions can also occur in Meckel’s cave.

Case Report: H3K27M-Mutant Glioblastoma Simultaneously Present in the Brain and Long-Segment Spinal Cord Accompanied by Acute Pulmonary Embolism

BACKGROUND

Glioblastoma multiforme (GBM) is a highly malignant glioma that rarely presents as an infratentorial tumor. Multicentric (MC) gliomas involve lesions widely separated in space or time, and MC gliomas involving supra- and infratentorial brain regions are rare. In most cases, the infratentorial lesion is seen after surgical manipulation or radiation therapy; it is typically located in the cerebellum or the cervical region, manifesting as metastasis originating from the brain. Besides, venous thromboembolism in brain tumors is usually seen after craniotomy.

CASE PRESENTATION

We present an uncommon adult case of symptomatic H3K27M-mutant MC glioblastoma simultaneously present in the brain, fourth ventricle, and cervical and lumbar spinal cord regions accompanied by acute pulmonary artery embolism in an adult woman who had not undergone previous therapeutic interventions. We also review the literature on this interesting presentation.

CONCLUSION

Our report highlights that clinicians should be alert to the potential alarming presentation of GBM. The incidence of spinal metastasis of cerebral GBM is increasing. Patients with a prior diagnosis of GBM with or without any new onset in the spinal cord should undergo an early MRI of the spinal cord to confirm the diagnosis at an early stage. While management of GBM remains controversial, more research is needed to explore molecular features of GBM further and develop novel targeted therapies for these patients.