RESUMEN
Manifestations of an atypical variant of medulloblastoma of the posterior fossa in extra-axial locations have been reported, and key questions concerning its interpretation have been raised previously. This review illustrated the clinico-radiological and histopathological features of the posterior fossa extra-axial medulloblastoma and described possible management strategies. We thoroughly reviewed all atypical anatomical locations of medulloblastoma reported within the posterior fossa and extra-axial spaces. The main characteristics of diagnostic imaging and histopathological results, primarily the distinctive radiopathological characteristics, were summarized to distinguish between intra- and extra-axial medulloblastoma, or pathologies mimicking this tumor. Most cases of posterior fossa extra-axial medulloblastoma have been reported in the cerebellopontine angle, followed by the tentorial and lateral cerebellar locations. The dural tail sign, which is commonly observed in meningioma, is rarely seen in intra- or extra-axial medulloblastoma and might be associated with other benign or malignant lesions. In addition to magnetic resonance imaging, the proposed new imaging techniques, including advances in modern neuroimaging modalities, were discussed, as potentially efficient modalities for characterizing extra-axial medulloblastoma. Radionuclide imaging and magnetic resonance perfusion imaging are practical alternatives to limit the number of differential diagnoses. We believe that medulloblastoma cases are likely under-reported because of publication bias and frequent tumors in unusual locations. Addressing these issues would help establish a more accurate understanding of this entity.
RESUMEN
BACKGROUND: Multiple cranial dural arteriovenous fistulas (dAVFs) are considered to be an uncommon vascular condition. dAVFs usually manifest with vague symptoms, which are related to the site of occurrence of the lesion and present with complex angio-architectural features, which in turn can render treatment procedures difficult. Appropriate treatment that aims to reduce the risk of intracranial bleeding and manage the patient's symptoms requires a multidisciplinary approach. CASE PRESENTATION: The patient was a 62-year-old man who developed symptoms of progressive right-sided otalgia and tinnitus. Cross-sectional imaging revealed long-standing venous congestion with intracranial hemorrhage in the right parieto-occipital region. Moreover, cerebral angiography demonstrated multiple complex dAVFs at the right transverse sinus-sigmoid sinus (TS-SS) junction, right posterior condylar confluence (PCC), and torcula. Treatment consisted of one session of endovascular treatment, in which transarterial Onyx embolization was used to treat the dVAF at the right TS-SS junction, transvenous coil embolization for the dVAF at the right PCC, and particle embolization for both occipital arteries feeding the torcular dAVF. Postoperative improvement with favorable clinical outcomes was observed at the patient's last follow-up visit. CONCLUSION: Multiple cranial dAVFs are an uncommon vascular lesion, which can present with unusual symptoms such as otalgia. Moreover, a single session of endovascular therapy can treat this lesion, ie, it can improve the patient's symptoms and provide a beneficial long-term outcome.