Houssein Darwish

Background: Masson tumor, also known as intravascular papillary endothelial hyperplasia (IPEH), is a benign reactive proliferation of endothelial cells that may present in various places in the body, most commonly in the head-and-neck region. It is more common in adolescents and adults and rarely presents as a lytic skull lesion in the pediatric population. Case Description: A 10-year-old right-handed previously healthy male presented with a painless, firm, gradually enlarging swelling over the right frontal scalp for 2 months but was otherwise neurologically intact. Computed tomography scan of the brain showed a lytic lesion in the right frontal bone with an enhancing soft-tissue component and a small dural/extradural extension and with no intracranial abnormality. Differential diagnoses included Langerhans cell histiocytosis (LCH) and, less likely, sarcoma. The patient underwent right frontal craniectomy with complete excision of the lytic lesion and cranioplasty reconstruction. Histopathology revealed papillary endothelial proliferation within a vascular lumen with positive reticulin staining, consistent with IPEH (Masson’s tumor), without malignant features. Conclusion: IPEH is a rare benign vascular lesion that may present as an osteolytic skull lesion, even in pediatric patients, and may be radiologically mistaken for more common or aggressive lesions such as osteosarcoma, Ewing’s sarcoma, or LCH, requiring histological analysis for confirmation. It should be considered in the differential diagnosis of pediatric lytic skull lesions, and complete gross total resection is typically curative.

Middle meningeal artery embolization (MMAE) has emerged as a safe and effective minimally invasive alternative to surgical evacuation of chronic subdural hematoma (cSDH), both as adjuvant therapy and as a stand-alone treatment. Despite its advantages, rare complications such as facial nerve palsy (FNP) may occur. Such complications have rarely been reported in the literature in the context of cSDH, with only 7 other cases. The authors present the case of FNP after MMAE for cSDH and highlight the mechanism of injury, management, and preventive strategies that should be considered prior to endovascular interventions, while summarizing the previously reported cases. Special attention must be given to the endovascular technique implicated and to the complex anatomy of the middle meningeal artery (MMA) to reduce the incidence of such complications. Management of such complications is extrapolated from the available literature on facial nerve injuries and is mainly supportive through eye moisturization, facial muscle rehabilitation, and steroids. Although no consensus has been reached for prevention, some recommendations have been given throughout the literature, such as distal microcatheter positioning, proximal mechanical blockage with balloon-assisted flow reversal, and the use of coil-only embolization or high-viscosity embolic agents with a particle size ≥ 150 μm. https://thejns.org/doi/10.3171/CASE25866

Background: Spinal subdural hematoma (SDH) is a very rare complication of percutaneous balloon kyphoplasty. Here, a 66-year-old male developed delayed-onset spinal SDH following kyphoplasty. Case Description: A 66-year-old male with a history of atrial fibrillation on Eliquis developed a SDH on day 4 following a T3 single-level kyphoplasty for an osteoporotic compression fracture. The patient presented with progressive lower extremity motor/sensory paralysis that eventually ascended to the cervical region. The magnetic resonance (MR) imaging revealed a large dorsal subdural hematoma extending from T1 to S2. The patient underwent a decompressive laminectomy for hematoma to remove cement fragments and repair a dural tear. Postoperatively, the patient partially recovered sensation but no motor function and expired in the intensive care unit due to major comorbid factors. Conclusion: SDH is a potentially serious risk of performing a kyphoplasty. This is particularly true for patients on anticoagulants who should be stringently monitored with MR if indicated to avoid a major postoperative hemorrhage and paralysis.

Background: Cerebral arteriovenous malformations (AVMs) are rare congenital vascular anomalies, often presenting with intracranial hemorrhage or seizures. Posterior reversible encephalopathy syndrome (PRES) is a distinct neurological condition characterized by vasogenic edema, primarily affecting posterior brain regions and typically associated with hypertensive crises, eclampsia, or immunosuppressive therapies. However, its occurrence following neurosurgical interventions is exceptionally rare. This case report documents the first instance of PRES following the resection of a Spetzler-Martin grade I frontal AVM, emphasizing the importance of early recognition and management of this rare complication. Case Description: A 27-year-old woman underwent navigation-assisted resection of a right frontal AVM. The procedure was uneventful; however, in the immediate postoperative period, she experienced a generalized tonic-clonic seizure, agitation, dysconjugate gaze, and altered consciousness. Brain magnetic resonance imaging revealed diffuse high fluid-attenuated inversion recovery signal abnormalities in the brainstem, cerebellum, thalami, basal ganglia, and cerebral hemispheres, consistent with central PRES. The patient was managed with supportive care, resulting in a full clinical and radiographic recovery within 3 weeks. Follow-up imaging confirmed the resolution of PRES-related changes, and she remained seizure-free after antiseizure medication tapering. Conclusion: This case underscores the critical importance of early neuroimaging in evaluating unexpected postoperative neurological symptoms. Recognizing central PRES and its atypical radiographic patterns enables timely diagnosis and appropriate management, avoiding unnecessary interventions. The pathophysiology likely involves postoperative endothelial dysfunction and disrupted autoregulation. This report underscores the importance of considering PRES in postoperative neurological complications and calls for further research into its mechanisms and optimal management.

Background: Colorectal cancer (CRC) is among the most widely prevalent malignancies afflicting increasingly high numbers of the population worldwide. Metastases majorly involve the liver and lungs but are not unheard of in the brain. Only one case has so far been reported to occur in the brainstem, excluding this one. Case Description: We report a second case of an 85-year-old male who presented with headaches and difficulty swallowing and was found to have a right anterior pontine lesion extending into the midbrain on magnetic resonance imaging of the brain and cecal adenocarcinoma on subsequent colonoscopy. The pontine lesion was biopsied and confirmed to be a metastatic lesion. He underwent a course of radiotherapy and tolerated it well, with improvement of his presenting symptoms. Conclusion: CRC-related morbidity and mortality are on the rise, as is expected with the incidence of metastases to the brain, including the brainstem, which is an extremely rare site for such metastases. This case illustrates such an encounter and the possibility of early detection of these metastases through brain imaging of patients with known or suspected CRC and symptoms of neurologic dysfunction. The current preferred management is surgical resection when possible, with or without radiotherapy. However, due to the rarity of the case, more data might be required to make more accurate decisions in these cases.

Background: Simultaneous sampling of the cingulate gyri through a single depth electrode inserted underneath the falx cerebri is clinically useful in certain cases of drug-resistant epilepsy. However, the frequency at which each region of the cingulate gyri – namely, anterior, middle, and posterior – can be simultaneously sampled with a single electrode remains uncertain. Methods: We assessed the anatomical relationship between the falx cerebri and the cingulate gyrus in 50 adults and children. Subsequently, we determined whether an arbitrary line, denoted as A (representing a 5 mm gap between the falx cerebri and corpus callosum necessary for depth electrode insertion), fell within the anterior, middle, or posterior cingulate gyrus. Results: The shape of the falx cerebri and its intersection point with the corpus callosum varied substantially across individuals, with a significant difference between children and adults (P = 0.02). The A line was located in the middle cingulate gyrus in 18 children (72%), while 3 (12%) and 4 (16%) had it located in the posterior and anterior cingulate gyrus, respectively. Among adults, 15 individuals (60%) had the A line in the middle cingulate gyrus, 10 (40%) in the posterior cingulate gyrus, and none in the anterior cingulate gyrus. Conclusion: This study demonstrates the feasibility of simultaneous sampling of both the anterior and middle cingulate gyri in adults and children. Moreover, it represents the first investigation to document the wide interindividual variability in the morphology of the falx cerebri and its association with the cingulate gyrus.

Background: Ventriculoperitoneal shunt (VP) insertion is one of the surgical treatments for patients with hydrocephalus. Infection, malfunction, catheter migration, hernia development, equipment failure, CSF subcutaneous collection and peritoneal pseudocyst formation are considered to be the main complications of this procedure. Case Description: A 6-months-old boy known to have congenital aqueductal stenosis with VP shunt insertion at the age of 1 month, presented with scrotal swelling and generalized hypotonia. He was found to have catheter migration into the scrotum. Conclusion: Scrotal migration of the distal end of the ventriculoperitoneal shunt is a rare but threatening complication that can present with either signs of hydrocephalus or scrotal swelling or hydrocele. Accordingly, we recommend performing a scrotal exam with an ultrasound early upon evaluation of any infant presenting with scrotal swelling or hydrocele after VP shunt insertion. There haven’t been clear recommendations in the literature concerning closure of patent processus vaginalis upon placing a VP shunt in patients below the age of 3 months. Thus, we question whether early closure could help reduce the complications of catheter migration in infants.

Contrast Induced Encephalopathy is a known but rare complication of endovascular procedures. Patients show neurologic symptoms mimicking a stroke and include visual disturbances, motor or sensory deficits, headache, seizures, memory loss, confusion, aphasia, and coma. Irreversible neurological symptoms are rare and fatal encephalopathy is even more so.

Background: Granular cell tumors (GCTs) are uncommon peripheral nerve sheath tumors of Schwann cell origin that may occur throughout the body. However, they rarely occur in the spinal canal. Case Description: A 49-year-old male presented with burning sensation in the left knee. The MRI of the lumbar spine showed an L3-L4 intradural extramedullary tumor. Complete surgical resection was successfully performed and the L3 root burning improved. Histopathologically, the lesion proved to be a benign GCT. Conclusion: Spinal GCTs are rare benign tumors that may be found in an intradural extramedullary location in the spine. The preferred treatment is complete surgical resection as subtotal/partial resection may result in recurrence warranting radiation therapy.