Neuroimaging Findings in Moebius Sequence.

BACKGROUND AND PURPOSE: Moebius sequence comprises a spectrum of brain congenital malformations predominantly affecting the function of multiple cranial nerves. Reported neuroimaging findings are heterogeneous and based on case reports or small case series. Our goal was to describe the neuroimaging findings of Moebius sequence in a large population of patients scanned with MR imaging. MATERIALS AND METHODS: An observational cross-sectional study was performed to assess brain MR imaging findings in 38 patients with Moebius syndrome studied between 2013 and 2016. RESULTS: Retrospective analysis of MR imaging studies showed flattening of the floor of the fourth ventricle floor secondary to a bilateral absent facial colliculus in 38 patients (100%) and unilateral absence in 1. A hypoplastic pons was found in 23 patients (60.5%). Mesencephalic malformations consisted of tectal beaking in 15 patients (39.5%) and increased anteroposterior midbrain diameter with a shallow interpeduncular cistern in 12 (31.6%). Infratentorial arachnoid cysts were found in 5 patients (13.2%), and cerebellar vermis hypoplasia, in 2 (5.3%). Supratentorial findings included the following: thalamic fusion (26.3%), periventricular nodular heterotopias (26.3%), ventriculomegaly (26.3%), callosal abnormalities (23.7%), and hippocampal malrotations (23.7%). CONCLUSIONS: Findings seen in this large patient cohort agreed with previously published reports. Flattening of the fourth ventricle floor secondary to a bilaterally absent facial colliculus was the most frequent MR imaging finding. The presence of other brain stem and cerebellar malformations as well as supratentorial abnormalities may help explain clinical symptoms and achieve a correct diagnosis.

Unicentric Castleman's disease in the posterior cervical space mimicking a schwannoma.

INTRODUCTION: Castleman's disease (CD) is a benign and rare lymphoid tissue disease of undetermined origin. It affects the neck infrequently; therefore its preoperative diagnosis is difficult and can be confused with other hypervascular lesions. CASE REPORT: We present a case of unicentric hyaline-vascular CD in the posterior cervical space (PCS) evaluated by MRI and initially presumed to be a cervical schwannoma. DISCUSSION: As shown with our case, unicentric CD should be included in the differential diagnosis for masses in the PCS, especially when a hypervascular lesion like a schwannoma is suspected. The finding of central low intensity areas in a fissured and radial pattern in T2 sequences can help to consider CD when dealing with PCS masses as shown by previous cases and our reported experience.