BACKGROUND AND PURPOSE: Menière disease (MD) manifests in 2 major endotypes: one with a hypoplastic, underdeveloped endolymphatic sac (MD-hp) and the other with a normally developed sac that degenerates over time (MD-dg). Determining the specific endotype in patients is important for predicting disease progression, tailoring patient counseling, and optimizing treatment strategies. Endotype diagnosis involves measuring an angular trajectory of the vestibular aqueduct (ATVA), with an ATVA ≥140° indicative of MD-hp and an ATVA ≤120° of MD-dg. However, assessing the ATVA can be challenging. This study aimed to explore the link between ATVA and the thickness of the retrolabyrinthine bone as an alternative diagnostic measure that could provide differentiation between MD endotypes using CT and MR imaging. MATERIALS AND METHODS: Retrospective review of CT temporal bone imaging from 32 adult patients with definite MD (60 ears) and 33 age-matched controls without MD or other inner ear symptoms (61 ears) was performed. The ATVA and retrolabyrinthine bone thickness were measured using uniform methodology on standardized axial CT images. Comparative analyses were performed to determine the correlation between ATVA and retrolabyrinthine bone thickness. Additionally, from a separate cohort of 11 patients (22 ears), CT and MR examinations of the temporal bone were retrospectively reviewed for retrolabyrinthine bone thickness measurements, to verify the correlation across the 2 modalities. RESULTS: The average retrolabyrinthine bone thickness was statistically significantly different between MD endotypes, being a mean of 0.8 (SD, 0.3) mm in patients with MD-hp (ATVA ≥140°) and 2.0 (SD, 0.9) mm in patients with MD-dg (ATVA ≤120°), with a consistent pattern of thin retrolabyrinthine bone in MD-hp and variable thickness in MD-dg. Receiver operating characteristic curve analysis within the MD cohort revealed that a retrolabyrinthine bone thickness ≥1.2 mm effectively rules out MD-hp. Excellent interrater reliability was noted for the retrolabyrinthine measurement, and there was near-perfect correlation between CT and MR measurements. CONCLUSIONS: Retrolabyrinthine bone thickness proved to be a useful and straightforward alternative marker for distinguishing MD endotypes, being particularly useful for excluding MD-hp. Including information on retrolabyrinthine bone thickness should be considered a routine part of reporting in the context of MD imaging.

Brain abscesses caused by Listeria monocytogenes (LM) are very rare and carry a high mortality risk. We present a patient with disseminated non-small cellular lung cancer (NSCLC) and multiple unusual LM brain abscesses. These abscesses have multiple elongated peripherally enhancing lesions in a characteristic formation that is “worm or tramtrack-like” following the white matter fiber tracts.

Solitary fibrous tumors (SFTs) are mesenchymal, fibroblastic tumors with mostly favorable, but still unpredictable prognosis. Their rarity and occurrence at a variety of locations coupled with variable histological appearance make the diagnosis a challenge. This can be resolved by histological and immunohistochemical analysis on the histologic material eventually coupled with demonstration of NAB2-STAT6 gene fusion by next generation sequencing (NGS) analysis. Tumor removal with clear surgical margins is sufficient for complete cure in most cases. Percutaneous transcatheter embolization in well-vascularized lesions may minimize the risk of bleeding during subsequent removal. In this article we present a rare case of SFT arising from the external auditory canal and treated with preoperative endovascular arterial embolization. A literature review with focus on diagnostics and treatment of this entity in the head and neck region is following.

SUMMARY: A handful of cases of protuberant fibro-osseous lesions of the temporal bones have been described in the literature to date, with primary focus on the pathologic features. Here we review 3 cases of pathology-proved protuberant fibro-osseous lesions of the temporal bone and include a literature review with a focus on the imaging features. While rare, these lesions have near-pathognomonic imaging features defined by a location at the cortex of the outer table of the temporal bone at the occipitomastoid suture, lack of involvement of the underlying marrow, variable mineralization, and MR signal characteristics atypical of a chondroid lesion. One case in this series was FDG-avid and had occasional mitotic features, possibly reflecting an aggressive variant. Neuroradiologists should be familiar with this benign diagnosis to aid in timely identification and avoid unnecessary additional imaging.