Osteoblastoma Mimicking an Idiopathic Intracranial Hypertension Syndrome

Sinus pericranii in the setting of a posterior fossa pilocytic astrocytoma: illustrative case

BACKGROUND

Sinus pericranii (SP) is a rare vascular anomaly, with an uncertain etiology. Often discovered as superficial lesions, they can be primary or secondary in nature. Herein, we report a rare case of SP in the setting of a large posterior fossa pilocytic astrocytoma associated with a significant venous network.

OBSERVATIONS

A 12-year-old male presented with acute clinical deterioration in extremis with a 2-month history of lethargy and headaches. Outside plain computed tomography imaging revealed a large posterior fossa cystic lesion, probably a tumor, with severe hydrocephalus. There was also a midline small skull defect at the opisthocranion, without visible vascular anomalies. An external ventricular drain was placed with rapid recovery. Contrast imaging revealed a large midline SP emanating from occipital bone with a large intraosseous, and subcutaneous venous plexus in the midline draining inferiorly into venous plexus around the craniocervical junction. A posterior fossa craniotomy without contrast imaging could have resulted in catastrophic hemorrhage. A small modified off-center craniotomy provided access to the tumor with a gross total excision.

LESSONS

SP is a rare but significant phenomenon. Its presence does not necessarily preclude resection of underlying tumors, provided that a careful preoperative assessment of the venous anomaly is undertaken.

Benign bony tumors of the paranasal sinuses, orbit, and skull base

Benign bony tumors of the skull base and paranasal sinuses are uncommon entities, with an overall higher incidence in males. Benign bony tumors may lead to local expansion with resultant mass effect of potentially critical structures. Some benign bony tumors may undergo malignant transformation. This article reviews the presentation and management of benign bone tumors of the skull base and paranasal sinuses with special consideration to involvement of the adjacent orbit, intracranial and critical neurovascular structures. This review covers tumor incidence, location, gross and histologic appearance as well as radiographic findings, treatment, and recurrence rates. Tumors discussed in this article include osteochondromas, osteomas, osteoid osteomas, aneurysmal bone cysts, fibrous dysplasia, giant cell tumors, cemento-ossifying fibroma, ameloblastic fibro-odontoma, ecchordosis physaliphora, chondromyxoid fibroma, primary chronic osteomyelitis, primary chronic osteomyelitis, osteochondromyxoma, and dense bone islands.

Venous hypertension caused by a meningioma involving the sigmoid sinus: case report

Background

Intracranial venous hypertension has been associated with a few cases of meningioma secondary to compression of the venous sinus. This is the rare case of small meningioma involving the sigmoid sinus leading to intracranial venous hypertension mimicking venous thrombosis.

Case presentation

A 39-year-old woman suffered visual dysfunction due to bilateral papilledema. Noncontrast head computed tomography (CT) showed no intracranial space-occupying lesions or hydrocephalus. Cerebrospinal fluid examination revealed high opening pressure. Various image inspections such as three-dimensional CT angiography, magnetic resonance imaging, and cerebral angiography demonstrated a small 2.5-cm lesion causing subtotal occlusion of the dominant right sigmoid sinus. No improvement of clinical manifestations was observed after medical treatment for 6 months, so right presigmoid craniectomy was performed. Operative findings revealed that the tumor was located predominantly involving the sigmoid sinus. The pathological diagnosis was fibrous meningioma. Postoperative fundoscopic examination showed improvement of bilateral papilledema.

Conclusions

We treated a patient presenting with intracranial hypertension due to a small meningioma involving the sigmoid sinus. This unusual case suggests that early surgical strategies should be undertaken to relieve the sinus obstruction.

Pediatric cranial osteoblastoma: Technical note of surgical treatment and review of the literature

Osteoblastoma of the skull is a rare entity, and they account only for 2-4% of all the cases of osteoblastoma. We perform a comprehensive review of the pertinent literature on the subject and we report a case of a 3-year-old girl presenting with a 6-month history of a supraorbital mass and exophthalmos due to an osteoblastoma of the frontal and ethmoid bones involving the orbit and anterior skull base. A 3D printed model of the patient's skull was used for the preoperative planning and reconstruction strategy. Total en-bloc resection of the tumor followed by immediate reconstruction was achieved. No recurrence was detected 3 years after the surgery. Gross total resection is strongly advised with skull osteoblastoma, especially in young age, because of the risk of the recurrence and malignant transformation. 3D printing is proven to be a valuable tool to enhance surgical performance by avoiding complications while achieving total resection with accurate reconstruction. Long-term follow-up is important to detect recurrences and improve the management of these young patients.