Screening in cryptogenic brain abscess: Do not forget pulmonary arteriovenous malformations.

BACKGROUND: Brain abscess usually occurs secondary to trauma, through contiguous spread (e.g.; dental infections, [paranasal] sinusitis, otitis, and mastoiditis), after intracranial neurosurgical procedures, or through hematogenous spread in case of an arteriovenous (AV) shunt, for example; atrial septum defect. Although uncommon, another possible cause of AV shunt which can facilitate brain abscess is a pulmonary arteriovenous malformation (PAVM). We report a case of brain abscess secondary to a solitary PAVM and review the literature. CASE DESCRIPTION: A 74-year-old male patient presented with headaches, fatigue, low-grade fever, and homonymous hemianopsia. He was diagnosed with a brain abscess in the left occipital lobe. A chest computed tomography (CT) with intravenous (IV) contrast was performed because of fever and respiratory insufficiency in a period where screening for COVID-19 in suspected patients was important. A solitary PAVM of the left lung was diagnosed. Initial stereotactic burr hole drainage of the abscess was insufficient and resection of the abscess was deemed necessary. Routine workup did not reveal any additional pathology apart from the PAVM. After treatment of the cerebral abscess, the PAVM was treated with embolization using an endovascular plug. CONCLUSION: It is recommended to screen for PAVM by chest CT with IV contrast in patients with brain abscess when no obvious source of infection can be identified.

Atlantoaxial instability in monozygotic twin sisters: degenerative or congenital disease?

The authors report on two 70-year-old monozygotic twin sisters who both suffered severe nontraumatic atlantoaxial instability. If either had been a solitary case, degenerative atlantoaxial instability would have been the most straightforward diagnosis. In this case report the authors attempt to answer the question of whether an underlying congenital predisposition might be involved.

Ependymomas of the filum terminale: The role of surgery and radiotherapy.

BACKGROUND: Ependymomas of the filum terminale (EFT) form a specific and relatively uncommon subtype of spinal cord ependymomas. Most series in the literature are small, spanning a large time period. Up to date no consensus has been reached about the optimal treatment of these lesions. Some authors promote postoperative radiotherapy for all cases, others advocate postoperative radiotherapy only when a subtotal resection is performed or when metastasis are apparent. METHODS: We performed a retrospective analysis of 22 patients with an EFT (mean age at diagnosis of 35.6 years). RESULTS: In all patients (9/22) with lesions smaller than 4.5 cm no metastases were present and a complete resection could be obtained. No adjuvant radiotherapy was performed and at latest follow they had an excellent outcome. In our series, these initial tumor characteristics were more important regarding prognosis than either histology or treatment-related factors. For the larger tumors, total resection was obtained less frequently, more dissemination was diagnosed and a worse outcome was scored. Radiotherapy if indicated did lead to an acceptable disease control. CONCLUSION: In every case of EFT, an individual treatment protocol has to be outlined, but if an EFT is relatively small and can be resected completely, we would advocate to withhold radiotherapy.

Migrating pseudomeningocele causing posterior fossa syndrome.

We present two cases of spontaneous intracerebellar migration of a pseudomeningocele. This is a rarely reported complication of posterior fossa surgery with possible life threatening cerebellar mass effect. The probable mechanism is a slow but progressive cerebrospinal fluid (CSF) movement (one-way valve mechanism) into the pseudomeningocele with secondary herniation or dissection through a weakened dura into the cerebellum causing progressive or acute cerebellar dysfunction. Evacuation and dural repair with or without CSF shunting or marsupialisation results in resolution of the symptoms.

Choroidal fissure cerebrospinal fluid-containing cysts: case series, anatomical consideration, and review of the literature.

BACKGROUND: Cerebrospinal fluid (CSF)-containing cysts at the level of the choroidal fissure are rare embryological entities infrequently described in the literature because of their benign nature. On the occasion of a case series, we present an overview of the literature and discuss anatomical and embryological location, imaging characteristics, presenting symptoms, and treatment indication of these lesions. METHODS: We identified, in a retrospective study of a database with 81 patients harboring 86 supratentorial intracranial cysts, six patients with a CSF-containing cyst at the level of the choroidal fissure. In all cases, presenting symptoms were mild and the cysts were considered a fortuitous diagnosis. None of the patients was treated surgically, and the cysts remained stable at radiological follow-up. We performed a literature search for cerebral cysts and choroidal fissure cysts in particular. RESULTS: Only one large study purely addressing choroidal fissure cysts was found in the literature. CONCLUSIONS: CSF-containing cysts at the level of the choroidal fissure may be of the arachnoid or the neuroepithelial type, but pathological confirmation of a CSF-containing cyst at this specific location has never been published. Very infrequently they are symptomatic, and surgical treatment is hardly ever necessary.

Extrusion of a ventriculoperitoneal shunt catheter through an appendicovesicostomy.

Migration of a ventriculoperitoneal shunt catheter is a rare but well-recognised complication in hydrocephalus treatment. Perforation into different organs or through natural or artificial orifices has been described. In this case, the shunt catheter has extruded through a Mitrofanoff appendicovesicostomy.

A patient with swelling of the eyelid: ancient schwannoma of the supraorbital nerve (2010:6b).

We present a case of swelling of the eyelid and supraorbital anesthesia caused by an intraorbital tumor. The differential diagnosis based on imaging consisted of aneurysmal bone cyst, schwannoma, neurofibroma, dermoid cyst, and cavernous hemangioma. The surgical and pathological diagnosis was an ancient schwannoma of the orbit, a rare entity.