Parapharyngeal Space Venous Malformation: An Imaging Mimic of Pleomorphic Adenoma

Venous malformations in the parapharyngeal space are rare and may be challenging to diagnose with imaging secondary to multiple overlapping features with pleomorphic adenoma, which is much more commonly found in this region. While both lesions are T1 isointense and T2 hyperintense relative to skeletal muscle and demonstrate contrast enhancement, more uniform T2 hyperintensity and progressive contrast pooling on delayed postcontrast T1WI may allow the radiologist to include venous malformation in the differential diagnosis. This is important because it has the potential to alter management from surgical resection to observation. The primary aim of this study was to review the imaging appearance of parapharyngeal venous malformations through a retrospective case series.

Pharyngeal amyloidomas: Variable appearance on imaging

Amyloidomas are rare tumor-like depositions of abnormally folded, insoluble proteins that may be seen in the setting of systemic amyloidosis or as isolated tumoral deposits. Focal, isolated amyloidomas carry an excellent prognosis whereas systemic amyloidoses do not. The ability to identify or suggest amyloidoma on imaging studies may help direct laboratory testing and eventual diagnosis. Amyloidomas involving the head and neck have been variably described from homogeneously T2 hypointense to iso-slightly hyperintense relative to skeletal muscle. Herein we present two patients with pharyngeal submucosal amyloidomas of differing sizes and imaging characteristics to emphasize their potential widely variable imaging appearance and broaden our knowledge of these rare lesions.

MRI-Based Texture Analysis to Differentiate Sinonasal Squamous Cell Carcinoma from Inverted Papilloma

BACKGROUND AND PURPOSE

Because sinonasal inverted papilloma can harbor squamous cell carcinoma, differentiating these tumors is relevant. The objectives of this study were to determine whether MR imaging-based texture analysis can accurately classify cases of noncoexistent squamous cell carcinoma and inverted papilloma and to compare this classification performance with neuroradiologists' review.

MATERIALS AND METHODS

Adult patients who had inverted papilloma or squamous cell carcinoma resected were eligible (coexistent inverted papilloma and squamous cell carcinoma were excluded). Inclusion required tumor size of >1.5 cm and preoperative MR imaging with axial T1, axial T2, and axial T1 postcontrast sequences. Five well-established texture analysis algorithms were applied to an ROI from the largest tumor cross-section. For a training dataset, machine-learning algorithms were used to identify the most accurate model, and performance was also evaluated in a validation dataset. On the basis of 3 separate blinded reviews of the ROI, isolated tumor, and entire images, 2 neuroradiologists predicted tumor type in consensus.

RESULTS

The inverted papilloma (n = 24) and squamous cell carcinoma (n = 22) cohorts were matched for age and sex, while squamous cell carcinoma tumor volume was larger (P = .001). The best classification model achieved similar accuracies for training (17 squamous cell carcinomas, 16 inverted papillomas) and validation (7 squamous cell carcinomas, 6 inverted papillomas) datasets of 90.9% and 84.6%, respectively (P = .537). For the combined training and validation cohorts, the machine-learning accuracy (89.1%) was better than that of the neuroradiologists' ROI review (56.5%, P = .0004) but not significantly different from the neuroradiologists' review of the tumors (73.9%, P = .060) or entire images (87.0%, P = .748).

CONCLUSIONS

MR imaging-based texture analysis has the potential to differentiate squamous cell carcinoma from inverted papilloma and may, in the future, provide incremental information to the neuroradiologist.

Is Hypoglossal Nerve Palsy Caused by Craniocervical Junction Degenerative Disease an Underrecognized Entity?

Isolated hypoglossal nerve palsy is uncommon, and underlying craniocervical junction degenerative disease has rarely been reported as an underlying cause. To improve understanding of this entity, we present a retrospective series of 18 patients with hypoglossal palsy in whom twelfth cranial nerve compression within the premedullary cistern or hypoglossal canal, or both, was found secondary to craniocervical junction juxta-articular cysts, retro-odontoid fibrous pseudotumors, and osteophytes. The imaging techniques and characteristic craniocervical junction degenerative disease lesion imaging findings presented here might help clinicians interpreting hypoglossal palsy imaging studies avoid perceptual and interpretive errors commonly found in the present series.

Dual-Acquisition Extracranial Computed Tomographic Angiography-Enhanced Neck Computed Tomography before Transoral Laser Microsurgery in Head and Neck Cancer Patients. Preliminary results

Transoral laser microsurgery (TLM) is an alternative surgical technique for piecemeal endoscopic resection of mucosal-based aerodigestive tract tumors. Though uncommon, potentially catastrophic postoperative bleeding may occur with this technique secondary to vascular injury along invasive tumor inner margins. We describe our preliminary results using a preoperative dual-acquisition extracranial computed tomographic angiography (CTA)-enhanced neck computed tomographic (CT) imaging and postprocessing protocol developed to improve visualization of mucosal-based head and neck tumors and adjacent arterial branches with the objective of facilitating TLM surgery and reducing secondary bleeding complications. Twenty patients with known head and neck cancers anticipated for TLM resection were selected for a dual-acquisition CTA-CT scanning and postprocessing protocol. The mucosal-based pharyngeal tumors and peritumoral vessel enhancement were compared on matched CTA and enhanced neck CT axial images. Operative reports and clinical notes were retrospectively reviewed to identify patients in whom the TLM surgical approach was altered or changed to conventional open surgery as a result of presurgical CTA-CT findings. Enhancement of peritumoral vasculature was almost uniformly superior (19 of 20 patients) on extracranial CTA compared with enhanced neck CT images. In six candidates for TLM surgery (30%), CTA findings resulted in a change in surgical approach to improve intraoperative peritumoral vascular control. In this small pilot series, primary tumor-peritumoral vessel relationships delineated by the addition of extracranial CTA to preoperative enhanced neck CT frequently impacted the surgical approach and facilitated TLM planning.

Posterior cerebral artery stenosis with midbrain infarction

BACKGROUND

Brain infarction secondary to stenosis of the posterior cerebral artery is uncommon. We report a patient with midbrain infarction and symptoms of both Benedikt's and pupil-sparing oculomotor palsy syndromes secondary to posterior cerebral artery stenosis.

CASE DESCRIPTION

A 51-year-old woman developed diplopia, left ptosis, and right hemiataxia and hyperactive tendon reflexes. Pupils were equal and reactive. Radiological examination revealed stenosis of the posterior cerebral artery and left-sided midbrain infarct.

CONCLUSIONS

Stenosis of the posterior cerebral artery may cause only midbrain infarction and may be responsible for Benedikt's and pupil-sparing oculomotor palsy syndromes.

Rhinocerebral mucormycosis: MR manifestations

Magnetic resonance (MR) examinations of three patients with rhinocerebral mucormycosis are reviewed. The clinical course is outlined and the MR characteristics are analyzed in light of the known pathology. The major MR findings include sinus and orbital disease followed by deep facial extension. Involvement of basal portions of the hemispheres, brain stem, and hypothalamus occurred rapidly following ipsilateral facial or orbital invasion in all three cases. Regions of intracerebral inflammation were hyperintense compared with normal parenchyma on T2-weighted and proton density-weighted images. Septic cavernous sinus and internal carotid artery thrombosis was diagnosed by MR in one case. Magnetic resonance demonstrated partial resolution of intracerebral abnormalities that accompanied clinical improvement in the one surviving patient.