Absent right common carotid artery with associated anterior communicating aneurysm: embryology and imaging correlation.

PURPOSE: To report an unusual absent right common carotid artery with embryological and clinical emphasis. METHODS: A 63-year-old female with a multilobulated anterior communicating artery saccular aneurysm was referred to our center for definite treatment. An analysis of her carotid system on CTA and DSA with 3D modeling was performed to assess the embryology of an absent right common carotid and its association with aneurysm development. RESULTS: Cerebral angiogram demonstrated an absent right common carotid artery and separate origin of the internal and external right carotid arteries arising from the brachiocephalic trunk. CONCLUSION: Absence of the common carotid artery is an uncommon anatomical variant, usually asymptomatic and commonly associated with other vascular abnormalities. It is important to be familiar with the association between this anatomical variant given its hemodynamic stress, high risk of stroke, and aneurysm formation.

Central nervous system embryonal tumor with PLAGL1 amplification: a case report of a novel entity focusing on imaging findings.

The embryonal central nervous system (CNS) tumor with PLAGL1 (pleomorphic adenoma gene-like) amplification is a novel type of pediatric neoplasm with a distinct methylation profile, described for the first time in 2022. It may be located anywhere in the neuroaxis and, as its name implies, it is driven by the amplification and overexpression of one of the PLAG family genes. Although the associated clinical, immunohistopathological, and molecular characteristics are well characterized in the seminal report of this entity, data on the radiological features is still lacking. Here, we present a case report of a 4-year-old girl with a biopsy-proven PLAGL1-amplified brainstem tumor and provide a detailed description of the corresponding conventional neuroimaging characteristics, aiming to better delineate this entity and to increase the awareness of this pathology in the radiological community.

An atypical location of pineoblastoma RB1 subgroup without pineal or retinal tumor.

PURPOSE: To describe the clinical and imaging features of a sellar-suprasellar pineoblastoma RB1 subgroup without pineal or retinal involvement. CASE REPORT: An 11-month-old girl presented to the emergency department with fever, rhinorrhea, vomiting, altered level of consciousness, and one seizure. Head CT and brain MRI demonstrated a large lobulated mass with calcifications and heterogeneous enhancement in the suprasellar region causing mass effect to the ventricular system and hydrocephalus. Histology revealed a CNS embryonal tumor not otherwise specified (NOS) with small round nuclei with mitotic activity and necrosis. DNA methylation analysis classified the tumor in the pineoblastoma RB1 subgroup. CONCLUSION: Pineoblastoma RB1 subgroup should be considered in the differential diagnosis of large sellar-suprasellar masses with calcifications and heterogeneous enhancement in children younger than 18 months even in cases of absent pineal or retinal involvement. Molecular analysis with DNA methylation profiling is critical for diagnosis and management.

A bicarotid trunk with associated right retroesophageal subclavian artery in a child with neurofibromatosis type 1 complicated by a left hemispheric stroke.

PURPOSE: To describe the association between two aortic arch branch variants and its possible relationship with neurofibromatosis-1. METHODS: A 5-year-old female with NF-1 diagnosis presented to the emergency department at 2 months of age with irritability, vomiting and left gaze deviation. Brain MRI showed a left side acute hemispheric stroke and left internal carotid occlusion. RESULTS: CT angiography of the neck showed the right and left common carotid arteries arising from a common vascular trunk coming from the aortic arch and a right retroesophageal subclavian artery. CONCLUSION: Although the relationship between NF-1 mutation and aortic arch branch abnormalities has not been described, there is a recognized condition known as neurofibromatosis/Noonan syndrome which is an accepted variant of NF-1 with clinical features of both NF-1 and Noonan syndrome caused by dysregulation of the RAS-MAPK pathway. Aortic arch branch variations in patients with NF-1 could be explained by this association.

Intradural Extramedullary Tumors and Associated Syndromes.

Most intradural tumors are located within the intradural extramedullary compartment, and the most common tumors are schwannomas and meningiomas. Other less common neoplasms include neurofibroma, solitary fibrous tumor, myxopapillary ependymoma, lymphoma, metastatic leptomeningeal disease, malignant peripheral nerve sheath tumor, and paraganglioma. Patients usually present with gait ataxia, radicular pain, and motor and sensory deficits due to chronic compressive myelopathy or radiculopathy. MRI is the modality of choice for detecting and evaluating intradural extramedullary spinal tumors. This imaging technique helps narrow the differential diagnosis and therefore decide treatment.

Multiple sclerosis with megacystic presentation: A case report.

Multiple sclerosis is a frequent condition where the diagnosis relies on clinical presentation, neurologic examination, cerebro spinal fluid markers, and diagnostic imaging tests; however, atypical variants of the disease can lead to misdiagnosis in some scenarios. Herein, we describe a case of a 24-year-old patient with multiple sclerosis with megacystic plaques, in which appropriate interpretation of the imaging findings lead to a proper diagnosis and treatment.

High jugular bulb with a diverticulum and vestibular aqueduct dehiscence: an anatomical variant to be aware in patients with hearing loss.

PURPOSE: To describe an anatomical variant that should be consider in patients with hearing loss. METHODS: An 8-year-old girl underwent to temporal bone computed tomography for the evaluation of bilateral conductive hearing loss and further assessment of possible enlarged vestibular aqueduct or high jugular bulb on brain magnetic resonance imaging (MRI). RESULTS: CT of temporal bone showed a cystic cavity with bony sclerotic margins extending from the right jugular foramen to the vestibular aqueduct. Bony dehiscence of the jugular foramen with the right carotid canal was also noted. On brain MRI, there was no evidence of enlargement of the endolymphatic duct and sac on T2 thin-section gradient echo sequence. Time of flight MR angiography did not show arterial flow in the cavity. Contrast enhanced MR venography confirmed the presence of a high right jugular bulb with a diverticulum extending into the vestibular aqueduct due to jugular bulb-vestibular aqueduct dehiscence. CONCLUSION: Knowledge of high jugular bulb-vestibular aqueduct dehiscence is important in the assessment of patients with otologic symptoms such as vertigo, tinnitus and hearing loss.

Papilledema: A Review of the Pathophysiology, Imaging Findings, and Mimics.

Increased intracranial pressure is the most common cause of papilledema. Multiple etiologies such as cerebral edema, hydrocephalus, space occupying lesions, infection, and idiopathic intracranial hypertension among others should be considered. Imaging plays a critical role in the detection of pathologies that can cause papilledema. MRI with contrast and CE-MRV, in particular, are key for the diagnosis of idiopathic intracranial hypertension. This review will focus in common and infrequent causes of papilledema, the role of imaging in patients with papilledema as well as its potential mimickers.