Extra-axial Mass Lesion Research Articles

Primary Extra-axial Glioblastoma Mimicking Meningioma: Case Report and Review of Literature

Glioblastoma (GBM) is the most common malignant brain tumour in adults. On radiology, diagnostic dilemmas can arise with other brain pathologies like metastasis, brain abscess, and lymphoma. However, GBM mimicking a meningioma on radiology has been rarely reported. Here, we report a case of GBM with magnetic resonance imaging (MRI) features suggestive of meningioma. A 46-year-old female presented with a one-month history of headaches. The MRI brain suggested a broad-based extra-axial mass lesion in the left frontal convexity with cerebrospinal fluid (CSF) cleft sign with compression of underlying brain parenchyma. Overall, the MRI brain was suggestive of a cystic meningioma. The patient underwent gross total resection of the tumour under microscopy, and final histopathology confirmed GBM. Although GBM is usually an intra-axial tumour, it may present as an extra-axial mass lesion with radiological features mimicking meningioma. Therefore, it should be considered a differential diagnosis in patients with an extra-axial tumour displaying atypical malignant features.

Traumatic middle meningeal artery aneurysm: a case report

IntroductionTraumatic intracranial aneurysms are rare, making up about 1% of all intracranial aneurysms. They can happen due to direct injury or blunt force, with the middle cerebral artery being the most frequent site.The middle meningeal artery (MMA) is the main artery that supplies the cranial dura mater, and, because of its location, is susceptible to damage after trauma. This article reported an unusual case of giant post-traumatic MMA pseudoaneurysm. CaseA 45 year-old man was referred to our department with a history of craniectomy. He complained of non-specific headache, but neurological examination was normal. A follow-up brain CT scan identified a right temporal fossa hyperdense mass. Digital subtraction angiography diagnosed a traumatic MMA aneurysm. The patient was treated with preoperative aneurysm embolization and surgical resection. DiscussionTraumatic MMA aneurysm is a rare presentation after head trauma. It can manifest as epidural hematoma, subdural hematoma or intraparenchymal hematoma, and sometimes resembles the present case, which was discovered incidentally. ConclusionPseudoaneurysm is a rare complication of MMA trauma, with late presentation. It should be considered in patients with history of traumatic brain injury and temporal fossa extra-axial mass lesion with vascular characteristics.

P-61 From Cushing to Nelson Syndrome: Diagnostic challenges and Surgical Dilemma

Abstract Introduction Diagnosis of the origin of ACTH-dependent Cushing's syndrome (CS) can be difficult in some cases, especially when MRI of the pituitary gland does not reveal an adenoma. Inferior petrosal (IPSS) or cavernous sinus sampling (CSS) with CRH stimulation helps confirm the central origin in most cases. CSS also helps lateralize the tumor within the pituitary gland with a sensitivity of 80%. Because transsphenoidal pituitary surgery is successful in the majority of MRI-negative cases, bilateral adrenalectomy is performed less frequently. Even with advanced radiologic studies, the origin may not be detected. Adrenalectomy may be an option in these cases. However, loss of feedback inhibition of the hypothalamic-pituitary-adrenal axis; can lead to aggressive transformation of an existing ACTH-secreting pituitary adenoma into Nelson's syndrome within 1-5 years. Clinical Case A 46-year-old female patient complaining of hot flashes and unable to lose weight was evaluated for CS and referred to the Department of Neurosurgery for a pituitary adenoma (Table 1). Since the adenoma was <6mm CSS with CRH stimulation was performed. The results did not support central origin (Table 2). Ectopic ACTH secretion was considered, but without finding the origin of the tumor on radiological examination, and treatment with ketoconazole and metyrapone was started for CS. However the patient then discontinued outpatient follow-up. The patient presented to our clinic 6 years later with a new pituitary MRI showing tumor growth (Fig.1b). She complained of fatigue and obesity. She was depressed and anxious. The skin on her face, hands and hump was dark and patchy (Fig.1c). During these years, she consulted several endocrinologists. MRI was performed annually. Brain MRI had showed a fronto-basal extraaxial mass lesion. The patient underwent microsurgical resection and pathology revealed a microcystic meningioma (WHO grade I). 3 months later bilateral nodular hyperplasia of adrenal gland was detected; she underwent bilateral laparoscopic adrenalectomy (no neoplasia). ACTH gradually increased up to 418pg/ml; the diagnosis of Nelson's syndrome was established. The patient underwent endoscopic transsphenoidal adenomectomy. The ACTH level was found to be 12pg/ml on the 2nd postoperative day. Pathological examination revealed a ACTH secreting pituitary adenoma (Ki-67:7%). CS patients suffer from emotional lability due to the effects of elevated cortisol and to the physical changes of their body. Proximal muscle weakness and obesity causes fatigue symptoms. The diagnosis is often delayed until complications occur. Differential diagnosis could be difficult and challenging. Patient's emotional lability could adversely affect treatment/follow-up compliance. The presented case had meningioma resection which could be delayed until remission from CD and bilateral adrenalectomy which could be avoided by endoscopic pituitary surgery. This case is a good example of the need for pituitary centers of excellence.Figure.Fig.1.a. MRI scan of the pituitary gland at first admission shows (a) a lesion extending posteriorly inferior to the right half of the pituitary gland, hyperintense at T2-weighted, iso-hypointense at T1-w, with heterogeneous contrast enhancement consistent with pituitary microadenoma (4mm*2mm) Fig.1.b. Progression in size of the adenoma (6mm*4mm) Fig.1.c. Darkening of the skin due to hypersecretion of ACTH. Table 1.Cavernous sinus sampling with corticotropin-releasing hormone stimulation Table 2.Laboratory tests in different times

Intracranial myeloid sarcoma as the first presentation of acute myeloid leukemia and literature review.

Intracranial myeloid sarcoma is a rare extramedullary presentation of acute myeloid leukemia (AML). Itcan involve the meninges and ependyma presenting as extra-axial mass lesion. Rarely, it can also invade the brainparenchyma. It is commonly seen in children. It is usually misdiagnosed due to its close resemblance to otherintracranial tumors (meningioma, metastasis, Ewing's sarcomas, and lymphoma). These are underdiagnosed ifthey precede the diagnosis of leukemia. A 7-year-old boy with isolated intracranial myeloid sarcoma who presented with raised intracranialpressure (ICP) which was successfully managed by surgical excision. Isolated intracranial myeloid sarcoma is a rare presentation of AML. Leukemia can be diagnosed earlyduring the postoperative period and can be started on therapy timely. These patients requires regular follow-ups(clinical, laboratory and radiological) to detect relapses early.

Is Brain MRI Essential for the Evaluation of Headache in Patients with Normal Neurological Examination?

Aim: Headache is amongst the most common reasons of consulting a doctor. In addition to impairing the quality of life of the individual, there are societal as well as fiscal outcomes like workforce loss along with health expenditures. MRI findings of patients with headache were examined retrospectively through the relevant literature with a view to scrutinizing the necessity of the very procedure carried out, and the results were shared accordingly. Through our study we delved into the recent situation in our country and investigated whether MRI devices with advancing and novel technologies give dissimilar results with diffusion and sensitivity-weighted images in the MRI findings of patients who seek medical advice visiting a health institution with complaint of headache. Materials and Methods: The study included 224 patients over the age of 18, who underwent brain MRI between January 2020 and December 2021 in our center, with normal findings on neurological examination and who had not undergone surgery. All abnormal appearances such as mass, metastasis, aneurysm, hydrocephalus, encephalitis, sinusitis, mastoiditis, otitis, which may cause secondary headache, were recorded in MR images. Results: Of the 224 patients, 120 (53.57%) were male and 104 (46.43%) were female. The mean age was 39.45±12.55 years. None of the 224 examinations revealed mass suspicious for malignancy, aneurysm, encephalitis, or meningitis. Extraaxial mass lesion compatible with meningioma was detected in 3 patients (1.33%), arachnoid cyst in 3 patients (1.33%), and developmental venous anomaly in 2 patients (0.89%). There was paranasal sinus infection in 145 patients (64.73%), mastoiditis in 37 patients (16.52%), and otitis in 8 patients (3.57%). The remaining 66 patients had no MRI findings except ischemic-gliotic changes, enlarged perivascular distances, and physiological calcifications. Conclusion: In studies designed according to CT and MRI examinations taken regardless of neurological examination and history, the rate of completely normal findings is quite high, as in our study. MRI scans conducted for these patients, who can indeed solely be diagnosed with examination or simpler imaging methods, lead to loss of time and money. In order to fix the said situation, we are of the opinion that the red flag practice should become widespread and nonessential examination requests should be supervised.

Primary marginal zone B-cell lymphoma of the cavernous sinus: a case report and review of the literature

BackgroundPrimary lymphoma of the cavernous sinus is a rare form of extranodal non-Hodgkin lymphoma, of which very few cases have been reported in the published literature. This report presents the MRI findings with apparent diffusion coefficient (ADC) value in an exceedingly rare primary marginal zone B-cell lymphoma (MZBCL) of the cavernous sinus.Case presentationThe case in this study is a 59-year-old immunocompetent male patient with a 2-month history of right ptosis and blurred vision. Right third cranial nerve palsy and binocular diplopia were observed upon neurological examination. Preoperative brain CT showed an extra-axial enhancing mass lesion in the right cavernous sinus. On MRI, ipsilateral internal carotid arterial encasement was noted without causing stenosis of the vessel. Isointense signal on T1-weighted and T2-weighted images, homogeneous contrast enhancement, and diffusion restriction were also observed. The mean ADC value of the tumor is 0.64 × 10–3 mm2/s (b value = 1000 s/mm2). Subtotal resection of the tumor was performed, and improvement of clinical symptoms were observed. The pathologic diagnosis of MZBCL was established by immunohistochemical examinations.ConclusionsPrimary MZBCL of the cavernous sinus is exceedingly rare, and preoperative confirmation poses a major challenge with CT and conventional MRI only. In this case, preoperative quantitative ADC value is shown to offer valuable additional information in the diagnostic process.

Sino Cranial Aspergillosis Mimicking Skull Base Meningioma- A Case Report and Review of Literature

Fungal infections of the nose and paranasal sinuses can be categorised into invasive and noninvasive forms. Central Nervous System (CNS) Aspergillosis is extremely rare in immunocompetent individuals. Invasive fungal sinusitis affecting CNS commonly poses a diagnostic dilemma on imaging, often confused with neoplastic processes. Here, Authors report a case of invasive sino cranial aspergillosis in immunocompetent individual mimicking a meningioma on imaging. A 46-year-old male patient presented with history of seizure like episode and right eye proptosis to Neurology Department. On Magnetic Resonance Imaging (MRI), there was enhancing T2 weighted hypointense extra-axial mass lesion along right frontal convexity with associated osseous erosion, intraorbital extension and associated sinus disease. Based on clinical presentation and imaging features, initial diagnosis of a aggressive neoplastic lesion was made. Patient subsequently underwent biopsy which showed fungal elements of Aspergillus Fumigatus species. Patient underwent endoscopic sinus surgery and along intravenous and oral antifungal therapy with good response to treatment. This case highlights the key role of imaging including MRI and CT in making accurate diagnosis of fungal sinusitis especially in immunocompetent individuals and differentiate from other entities like meningioma.

Intracranial Extraskeletal Mesenchymal Chondrosarcoma

Background: Mesenchymal chondrosarcoma (MCS) is a rare and aggressive malignant tumor, a subtype of chondrosarcoma assumed to arise from remnants of the embryonic cartilage or metaplasia of meningeal fibroblasts. Intracranial extraskeletal MCSs are rare tumors, accounting for <0.16% of intracranial tumors. They usually occur in the age group of 20–30 years and are commonly found in the frontoparietal region arising from the falx and surrounding dura. Case Description: A 17-year-old girl presented with weakness of the right lower limb. Magnetic resonance imaging showed a large lobulated extra-axial mass lesion in the left parasagittal frontal region. She underwent a left frontoparietal craniotomy and excision of the tumor. She received adjuvant radiotherapy 60Gy/30 fractions. Conclusion: Intracranial MCSs are rare malignant tumors with a poor prognosis. The prognosis depends upon surgical resection and postoperative radiotherapy.

Diagnosis of Acoustic Neuroma through Telemedicine

A 65-year-old male individual presented to an electronic urban primary health center with complaints of impaired hearing in the left ear, loss of sensations on the left side of the face, loss of sensation of taste of the left side of the tongue, and tingling and numbness of the left side of the face for 2 months. He had a history of diabetes for 8 years and hypertension for 5 years and on regular medication. The patient was completely evaluated by the medical officer and referred to a general medicine doctor for teleconsultation. The general medicine specialist had clinical evaluation, and after detailed discussion with the medical officer, he was referred to a neurosurgeon for further evaluation and management to Guntur Medical College. He had evaluated the client and recommended magnetic resonance imaging scans, and imaging revealed an extra-axial cerebellopontine angle solid mass lesion of size 3 cm × 2 cm with cystic component, arising from the left internal auditory canal causing mass effect on the middle cerebellar peduncle, suggestive of left acoustic neuroma without mass effect. He had specialized radiation therapy of 30 fractions of 25 gray in 5 cycles from July 20 to August 5, 2019, currently on regular medication for diabetes and hypertension and Vitamin B12 supplements, and follow-up scheduled in July 2020.

An Unusual Intracranial Collision Tumor of Anaplastic Ependymoma and Atypical Meningioma

Abstract The close geographic association of two or more synchronous primary brain tumors is an unusual occurrence. There are around 50 case reports of these intracranial collision tumors, mostly consisting of malignant astrocytoma (mainly glioblastoma) and meningioma. We present a rare intracranial collision tumor consisting of anaplastic ependymoma and atypical meningioma. To our knowledge, this is the first reported case of intracranial collision tumor with this combination. The patient is a 33-year-old gentleman who presented 2 years ago with new-onset intermittent headaches with increasing severity and associated blurry vision and vomiting. On imaging, he was found to have a 4.2 × 4.1 × 4.1-cm cystic-solid and heterogeneously enhancing extra-axial mass lesion in the left frontal lobe, with an enhancing dural tail. Histologic examination of the surgically excised lesion showed two geographically distinct areas of an extra-axial atypical meningioma (World Health Organization grade II) and an intra-axial anaplastic ependymoma (World Health Organization grade III). The anaplastic ependymoma component showed increased cellularity, pseudorosettes, microvascular proliferation, necrosis, and increased mitoses. It was diffusely positive for GFAP and had a Ki-67 proliferation index of 40%. The atypical meningioma showed 5 mitoses per 10 high-power fields. It had a membranous EMA immunoreaction and a Ki-67 proliferation index of approximately 20%. Recently, the patient had a recurrence of the anaplastic ependymoma component only. So far, no clear explanation has been found in the literature to understand the mechanisms leading to collision tumors. Since our patient does not appear to have any syndrome, it may represent a sporadic phenomenon; however, the sharing of a common oncogenic insult or any underlying molecular/genetic mechanism leading to synchronous tumorigenesis remains to be elucidated in this case.

Aggressive osteoblastoma with degeneration to secondary aneurysmal bone cyst

ABSTRACT A 4-year-old male patient presented with headaches that started 18 months ago and were associated with progressive loss of balance and difficulty walking. Magnetic resonance imaging (MRI) demonstrated an expansile extra-axial mass lesion in the posterior aspect of the posterior fossa on the left, compressing the adjacent brain, as well as the cerebellar hemispheres; it also distorts the fourth ventricle with severe obstructive hydrocephalus upstream. Histological evaluation diagnosed aggressive osteoblastoma with a secondary aneurysmal bone cyst of the skull. We report a case of aggressive osteoblastoma in which the lesion in the MRI was mimicking brain tumor or intracranial primary tumor rather than primary bone tumor.

From the Annals of Weill Cornell Neurological Surgery.

Prognosis in patients with traumatic brain injury (TBI) and Glasgow Coma Scale (GCS) score of 3 is poor, raising concern regarding the utility of aggressive operative neurosurgical management. Our purpose was to describe outcomes in a propensity matched population with TBI and GCS3 treated with operative neurosurgical procedures of craniotomy or craniectomy (CRANI).We conducted a five-year, multicenter retrospective cohort study of patients with an ED GCS 3 and a positive head CT identified by ICD-9CM diagnosis codes. Two populations were examined: (1) patients with extra-axial mass lesion (subdural or epidural haematoma), (2) patients without mass lesion (subarachnoid and intraparenchymal haemorrhage including contusion, other intracerebral haemorrhage or intracranial injury including diffuse axonal injury). In patients with extra-axial mass lesion, propensity score techniques were used to match patients 1:1 by CRANI, and the following outcomes were analysed with conditional logistic regression: survival, favourable hospital disposition to home or rehabilitation, and development of complications.There were 541 patients with TBI and GCS3; 19% had a CRANI, 83% were initiated within 4 h. In those with mass lesion, 27% (91/338) had a CRANI; after matching, a significant survival benefit was observed with CRANI vs. without CRANI (65% vs. 34% survival, OR: 3.9 (1.6–10.5) p < 0.001). There was borderline increased odds of favourable disposition (43% vs. 26%, OR: 2.4 (0.99–6.3, p = 0.052) with CRANI vs. without CRANI, and no difference in developing a complication (58% vs. 48%, OR: 1.5 (0.7–3.4), p = 0.30).Survival was achieved in 65% of patients that underwent surgical intervention for subdural and epidural haematoma, despite a presenting GCS of 3. These results demonstrate prompt operative neurosurgical management of mass lesion is warranted for selected patients with a GCS of 3, contributing to a significant 4-fold survival benefit. In the absence of mass lesion the effect of immediate neurosurgery on outcomes is inconclusive.

Giant Globular (Biconvex) Chronic Subdural Hematoma

Introduction Hydrocephalus is a frequent neurological condition in childhood. The most common approach to this disease is still ventricular shunting. However, shunting problems, including catheter infection or shunting malfunctioning, contribute to several complications, such as extra-axial hematomas, which are a possibly life-threatening. Case report We report the case of a 6-month-old female infant victim of brain trauma. She was previously shunted because of an obstructive hydrocephalus consequent of an aqueductal stenosis diagnosed early after birth. After brain injury, initial symptoms were only irritability and horizontal nystagmus. A computed tomography scan revealed an extra-axial mass lesion that suggested a giant globular extradural hematoma. The patient was submitted to a small exploratory craniectomy to evacuate the blood clot. Surprisingly, the supposed extradural hematoma was, in fact, a chronic subdural hematoma with an unusual shape. After the surgical drainage, the patient remained asymptomatic. No lesion recurrence has been detected so far. Conclusions The case illustrates a very uncommon and interesting presentation of a common neurosurgical disease. A full characterization of the lesion and its pathophysiology is made, and a particular surgical management is proposed and thoroughly discussed.

Aggressive operative neurosurgical management in patients with extra-axial mass lesion and Glasgow Coma Scale of 3 is associated with survival benefit: A propensity matched analysis.

Prognosis in patients with traumatic brain injury (TBI) and Glasgow Coma Scale (GCS) score of 3 is poor, raising concern regarding the utility of aggressive operative neurosurgical management. Our purpose was to describe outcomes in a propensity matched population with TBI and GCS3 treated with operative neurosurgical procedures of craniotomy or craniectomy (CRANI). We conducted a five-year, multicenter retrospective cohort study of patients with an ED GCS 3 and a positive head CT identified by ICD-9CM diagnosis codes. Two populations were examined: (1) patients with extra-axial mass lesion (subdural or epidural haematoma), (2) patients without mass lesion (subarachnoid and intraparenchymal haemorrhage including contusion, other intracerebral haemorrhage or intracranial injury including diffuse axonal injury). In patients with extra-axial mass lesion, propensity score techniques were used to match patients 1:1 by CRANI, and the following outcomes were analysed with conditional logistic regression: survival, favourable hospital disposition to home or rehabilitation, and development of complications. There were 541 patients with TBI and GCS3; 19% had a CRANI, 83% were initiated within 4h. In those with mass lesion, 27% (91/338) had a CRANI; after matching, a significant survival benefit was observed with CRANI vs. without CRANI (65% vs. 34% survival, OR: 3.9 (1.6-10.5) p<0.001). There was borderline increased odds of favourable disposition (43% vs. 26%, OR: 2.4 (0.99-6.3, p=0.052) with CRANI vs. without CRANI, and no difference in developing a complication (58% vs. 48%, OR: 1.5 (0.7-3.4), p=0.30). Survival was achieved in 65% of patients that underwent surgical intervention for subdural and epidural haematoma, despite a presenting GCS of 3. These results demonstrate prompt operative neurosurgical management of mass lesion is warranted for selected patients with a GCS of 3, contributing to a significant 4-fold survival benefit. In the absence of mass lesion the effect of immediate neurosurgery on outcomes is inconclusive.

Solitary Melanoma of the Central Nervous System

Primary melanoma of the central nervous system (CNS) is a rare entity, thus the diagnostic and therapeutic experience is based on a limited number of published cases. The diagnostic dilemma of solitary CNS melanoma is whether it is primary. Primary CNS malignant melanoma has more favorable prognosis than metastatic disease according to the published reports in the literature. Primary melanoma of the CNS may occur as intra-axial or extra-axial mass lesions or may be presented as meningeal spread. We describe the clinical features of 23-year-old male patient with solitary cerebral melanoma, including magnetic resonance imaging and histopathologic findings in light of literature.

Freiburg Neuropathology Case Conference: Widespread Mass Lesions After Resection of a Glioblastoma Multiforme

an 80-year-old male patient presented with intermittent aphasia, focal seizures with speech arrest and gait disturbance. Magnetic resonance imaging (MRi) revealed a contrast-enhancing lesion in the left temporal lobe (Fig. 1). a left temporal craniotomy was performed and a complete microsurgical resection of the lesion was achieved as demonstrated by early postoperative MRi (not shown). neuropathological analysis revealed a glioblastoma multiforme WHO grade iV. The neurological symptoms resolved completely. The patient was treated with external beam radiation therapy (60 Gy). Four months after surgery, he presented with fatigue and reduced general condition. MRi revealed a contrast-enhancing rim around the resection cavity and a subdural hygroma with compression of the sulci of the left hemisphere (Fig. 2). He was treated with a subdural drainage for 3 days. although the symptoms improved, computed tomography (CT) showed no resolution of the subdural effusion. The patient received four cycles of standard temozolomide chemotherapy (200 mg/m2, 5/28 pattern). eight months after the surgery, the follow-up MRi revealed multiple intraand extraaxial contrast-enhancing mass lesions located supraand infratentorially (Fig. 3). Meanwhile, the patient had developed a right-sided facial paresis and hearing loss, dysmetria and severe ataxia. Open biopsy was performed and an intradural, extracerebral lesion in the right parietal area was excised. The patient was transferred into palliative care.

Remote intracranial parenchymal hemorrhage in susceptibility-weighted imaging

A 45-year-old female presented to hospital with blurred vision and left homonymous hemianopia. MRI showed an extraaxial mass lesion over right occipital region. The patient underwent resection of the mass, which revealed a meningioma. She tolerated the …

Lung Cancer Metastasis to the CN VII/VIII Complex Mimicking Acoustic Neuronoma

A 60-year-old male patient presented with complaints of hearing loss, balance disturbance, and headache, with related findings on physical examinations. Neuroradiological evaluation showed a left-sided extra-axial mass lesion of the cranial nerve VII/VIII complex in the cerebellopontine angle. The patient was operated with preliminary diagnosis of acoustic neuronoma. Intraoperatively, the tumor was purely extra-axial in the cranial nerve VII/VIII complex with an extension into the internal meatus. However, an intraoperative view of the tumor was different from classical acoustic neuronoma; therefore, a frozen section examination was performed, which revealed adenocarcinoma of unknown origin. Postoperative histopathological examination confirmed the diagnosis of adenocarcinoma, and postoperative systemic scans revealed a mass lesion on the right lung on a computed tomography scan. The patient was then referred to medical and radiation oncology clinics for further evaluation and treatment.

Prevalence of asymptomatic vasogenic edema in pretreatment Alzheimer's disease study cohorts from phase 3 trials of semagacestat and solanezumab

Cerebral vasogenic edema (VE) has been reported to occur during antiamyloid immunotherapy. VE may be associated with central nervous system pathology with blood-brain barrier disruptions; however, less is known about the prevalence of naturally occurring VE in patients with Alzheimer's disease (AD). Fluid-attenuated inversion recovery imaging sequences were obtained from four ongoing multicenter, randomized, double-blind, placebo-controlled, phase 3 trials in patients with mild-to-moderate AD. The first set of baseline scans was from patients in volumetric magnetic resonance imaging addenda in the Interrupting Alzheimer's Dementia by EvaluatiNg Treatment of Amyloid PaThologY (IDENTITY) studies examining semagacestat, a γ-secretase inhibitor (cohort 1, n = 621). The second set of baseline scans was from the EXPanding alzhEimer's Disease InvestigaTIONs (EXPEDITION) studies examining solanezumab, an anti-Aβ monoclonal antibody (cohort 2, n = 2141). Readers were blinded to patient-identifying information and future treatment. A third set of baseline scans was from the first 700 patients who underwent protocol-specified magnetic resonance imaging before randomization in the EXPEDITION studies (cohort 3). The analysis used three neuroradiologists: two performed independent primary interpretations and the third was the adjudicator. Readers were blinded to patient information, treatment, protocol, and time point. Four cases of asymptomatic VE were detected at baseline/screening. Two VE cases were due to underlying extra-axial mass lesions. The third VE case was associated with numerous microhemorrhages in keeping with cerebral amyloid angiopathy-related inflammation or Aβ-related angiitis. The final VE case demonstrated localized sulcal fluid-attenuated inversion recovery imaging hyperintensity. No VE was detected in cohort 3 by readers blinded to patient baseline status. VE seems to be rare at baseline in patients with AD in clinical trials, 2 of 2,762 associated with AD. Additional cohorts should be evaluated to support these findings.

Lipomatous meningioma: Diagnostic pitfalls and pathological updates

We present a case of histologically confirmed lipomatous meningioma, the first to our knowledge reported in Hong Kong. A 75-year-old woman presented to us with on and off dizziness for 1 month. Computed tomography (CT) of the brain showed an extra-axial mass lesion containing fat and solid enhancing foci at her right frontal region. The definitive diagnosis could be made preoperatively. Postoperative histological examination of the tumour revealed the diagnosis of lipomatous meningioma. We have reviewed the literature and discussed the diagnostic clues, clinical presentation and pathology of this rare tumour.