Weindling, Steven M.

ObjectivesBiphenotypic sinonasal sarcoma (BSS) is a new, rare tumor characterized by concomitant neural and myogenic differentiation. The aim of this study is to describe the imaging characteristics and clinical outcomes of this neoplasm.MethodsA retrospective review of BSS patients surgically treated within a tertiary academic health care system was performed. Imaging characteristics and clinical outcomes were reviewed.ResultsFive patients underwent surgical resection of BSS tumors. Negative surgical margins were achieved in four (80%) patients. There were no deaths but two (40%) patients developed local recurrences during the postoperative follow‐up period (median follow‐up 31.4 months). Review of imaging characteristics revealed a median tumor size of 3.8 cm in greatest dimension. All tumors were unilateral and centered within the nasoethmoidal region. In all cases, the tumors extended to the nasal septum, lamina papyracea, and anterior skull base with variable degrees of erosion through these structures. On CT, involved bony structures demonstrated mixed lytic and sclerotic pattern, with definitive hyperostotic bone identified in four (80%) cases. On MRI, tumors were isointense‐to‐mixed iso/hypointense on both T1‐ and T2‐weighted sequences with one tumor demonstrating mixed T2 hyperintensity. All cases demonstrated gadolinium contrast enhancement.ConclusionsBSS is a locally aggressive tumor with a low risk of regional or distant metastases but has a significant rate of recurrence even with adequate resection. Despite its rarity, BSS should be considered in the differential diagnosis when imaging demonstrates a unilateral nasoethmoidal mass that is predominantly isointense to cerebral gray matter on T2‐weighted MRI and is hyperostotic on CT.Level of Evidence4

ObjectiveThe purpose of this article was to provide a combined pathologic and radiologic review of previous pathologically diagnosed facial nerve “hemangiomas” to confirm that these lesions are most characteristic of venous malformations rather than neoplasms.Study DesignRetrospective radiologic, clinical, and histopathologic review of all patients with a previous pathologically diagnosed facial nerve hemangioma of the temporal bone who underwent computed tomography or magnetic resonance imaging (MRI) were included. A consensus radiologic review for characteristic features and pathologic analysis was performed.Materials and MethodsA panel of 4 neuroradiologists retrospectively analyzed CT and MRI exams for 11 facial nerve hemangiomas and provided a consensus agreement on the characteristic imaging features. Concurrently, two neuropathologists reevaluated archived tissue specimens from these lesions and applied additional immunohistochemical and histochemical stains including D240, CD31, smooth muscle actin (SMA), Verhoeff Van Gieson (VVG) and glucose transporter 1 (GLUT1).ResultsLesions were composed of dilated vascular spaces with a simple, CD31‐positive endothelial lining and a smooth muscle component. All lesions were negative for markers found in arterial and lymphatic malformations and infantile hemangiomas. They had characteristic radiologic features previously ascribed to facial nerve hemangiomas. Namely, these lesions are typically T1 isointense or hypointense and T2 hyperintense relative to cerebral cortex and heterogeneously enhance on MRI. Bony canal expansion and erosion, intralesional calcification, and intracranial extension are common.ConclusionsOn the basis of this radiologic and pathologic review, these lesions are best characterized as venous malformations.Level of Evidence4

Otolaryngologists are called upon to evaluate and treat sinonasal masses discovered incidentally on imaging studies. Although common conditions such as sinonasal polyps and mucus retention cysts predominate, it is prudent practice to formulate a differential diagnosis to identify unusual conditions. We present a case of a maxillary sinus mass in a 78-year-old man that was discovered incidentally on brain imaging and subsequently identified on biopsy as an angiomyolipoma (AML). AMLs are benign hamartomatous tumors that rarely occur in extrarenal locations. Only a few cases have been reported in the nasal cavity. We believe our case represents the first reported instance of AML arising within a maxillary sinus. Identification of intratumoral fat within the mass on imaging studies may suggest the diagnosis of AML preoperatively. Close interdisciplinary collaboration among the otorhinolaryngology, radiology, and pathology services is beneficial for patient management. We report this case to raise awareness that AML can arise in this previously unreported location. Moreover, we wish to emphasize that AML should be considered in the differential diagnosis when imaging studies demonstrate a well-defined, heterogeneous, fat-containing solitary mass in the nasal cavity or maxillary sinus.

Objective The aim of this study was to perform an updated review of the imaging features of dysplastic cerebellar gangliocytoma (DCG). Methods Imaging findings were retrospectively reviewed in 14 patients with DCG. The analysis included size, location, cyst formation, calcification, intralesional hemorrhage, enhancement pattern, and apparent diffusion coefficient (ADC). Results In addition to revisiting many well-established imaging features of DCG, enhancement was much more common (64.3%) than previously reported, and small enhancing veins were also frequently encountered within or along the periphery of the lesions (50%). Dysplastic cerebellar gangliocytomas had an elevated ADC compared with normal cerebellum (967.8 ± 115.7 vs 770.4 ± 47.3 × 10−6 mm2/s; P < 0.0001). Conclusions Enhancement on magnetic resonance imaging within DCG should be an accepted imaging finding rather than being viewed as uncommon or atypical. Dysplastic cerebellar gangliocytomas typically have an elevated ADC compared with normal cerebellum, which may assist in differentiation from other posterior fossa neoplasms.

Objective: Evaluate prevalence and pattern of occipital pneumatization (OP). Patients: Individuals with imaging evidence of OP on computed tomography (CT). Intervention(s): High resolution CT scans of the temporal bone. Main Outcome Measure: The prevalence and pattern of OP on 1000 CT scans performed at a large academic healthcare system. Results: OP had a prevalence of 11.8% (n = 118) while occipital condyle pneumatization occurred in only 0.3%. Occipital air cells were right-sided in 27.1% (n = 32), left-sided in 51.7% (n = 61), and bilateral in 21.2% (n = 25), and OP was contiguous with the occipitomastoid suture. In cases of unilateral OP, the contralateral jugular foramen demonstrated relative enlargement ( p = 0.006), but a direct association could not be established. Conclusions: The occipital bone is an accessory site of skull base pneumatization in 11.8% of the population undergoing temporal bone CT, while air cell extension into the occipital condyle occurs more rarely. These occipital air cells have a left-sided predilection and are always in direct proximity to the occipitomastoid suture, suggesting developmental egress from the mastoid. OP is a normal variant and lacks features of craniocervical pneumatization, which is a rare disorder.

ObjectiveTo determine whether machine learning can accurately classify human papillomavirus (HPV) status of oropharyngeal squamous cell carcinoma (OPSCC) using computed tomography (CT)-based texture analysis.MethodsTexture analyses were retrospectively applied to regions of interest from OPSCC primary tumors on contrast-enhanced neck CT, and machine learning was used to create a model that classified HPV status with the highest accuracy. Results were compared against the blinded review of 2 neuroradiologists.ResultsThe HPV-positive (n = 92) and -negative (n = 15) cohorts were well matched clinically. Neuroradiologist classification accuracies for HPV status (44.9%, 55.1%) were not significantly different (P= 0.13), and there was a lack of agreement between the 2 neuroradiologists (κ = −0.145). The best machine learning model had an accuracy of 75.7%, which was greater than either neuroradiologist (P< 0.001,P= 0.002).ConclusionsUseful diagnostic information regarding HPV infection can be extracted from the CT appearance of OPSCC beyond what is apparent to the trained human eye.