Intracranial subdural osteoma: a rare benign tumor that can be differentiated from other calcified intracranial lesions utilizing MR imaging

Subdural osteoma in an adolescent patient with epilepsy: an unusual case report and literature review

OBJECTIVE

Subdural osteoma (SO) is a rarely reported benign tumor, and there is no report of SO manifested with epileptic seizures. We aim to further the understanding of SO-related epilepsy.

METHODS

Here, we report a meaningful case of epilepsy secondary to SO. A systematic review of the literature about SO using the electronic database PubMed and Web of science up to December 2022 was conducted.

RESULTS

A 15-year-old girl presented with epileptic seizures for 8 years. Magnetic resonance imaging revealed an irregular lesion with heterogeneous signal in the right frontal convexity. Right frontal craniotomy was performed to remove the lesion. The pathological diagnosis was SO. Histological analysis revealed that the mechanosensitive ion channels Piezo 1/2 were upregulated in the brain tissue compressed by the osteoma, compared with the levels in the osteoma-free region. Seizure freedom was obtained during the 6-month follow-up after the surgery. We identified 24 cases of SO in 23 articles. With our case, a total of 25 cases with 32 SOs was included. Of 25 cases, 24 are adults, and 1 is a child. Seizure has been reported only in our case. Frontal osteoma was found in 76% of the patients. Symptoms were cured in 56% of the patients after surgery.

CONCLUSION

Surgery is a safe and effective approach to the treatment of symptomatic osteoma. Mechanical compression on cerebral cortex may be a predisposing factor of the epileptogenesis caused by the SO.

Solitary subdural osteomas: Systematic review of the literature with an illustrative case

Background

Subdural osteomas represent an extremely rare entity with only 20 cases described to date. Despite the typical benign behavior, these tumors can grow to compress the brain and occasionally detach from the dura mater.

Methods

A systematic search of the literature was performed in compliance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. After screening for duplicates, 179 publications met the eligibility criteria. Finally, 18 manuscripts were included in this review. Moreover, a detailed description of an illustrative case is provided.

Results

The median age at diagnosis was 43.2 years, showing a female prevalence. The inner table of the frontal bone was reported as the most frequent location, and in six cases, the lesions did not show any relation with the dura, which appeared intact. Surgical resection appears to be an effective and safe management option. In the present work, the case of a 60-year-old female who presented with persistent, diffuse headaches which had first occurred 6 months earlier is described. On admission, the physical and neurological examinations were unremarkable, and her medical history disclosed no systemic disease, meningitis, or head injury. Computed tomography showed a homogeneous, high-density nodule attached to the inner table of the left middle cranial fossa.

Conclusion

In addition to an in-depth case description, the first systematic and qualitative review of the literature on intracranial subdural osteomas using the PRISMA is provided.

A Rare Occurrence of Multiple Intracranial Osteomas in the Cranial Cavity of a Cadaver With a Short Review on Subdural Osteoma

Osteomas are most common among all primary bone tumors of skull bones. They are usually asymptomatic due to their small size and slow growth. They are found incidentally on imaging studies for other neurologic symptoms. Osteoma may be single or multiple when present. They should be differentiated from meningiomas, chordomas, schwannomas, and parosteal osteosarcoma by using different diagnostic methods, including histopathologic study.

During routine dissection for MBBS students in an 87 years old female cadaver, we found multiple (seven in number) irregular, lobulated bony masses/structures. Their positions were different with respect to the layers of meninges. Some were present between the dura mater and arachnoid mater compressing the adjacent brain tissues forming impressions on them, and some were outside the dura mater. So, into the previously existing classification, we want to add a new variety under the type b category, i.e., mixed type (intraparenchymal, dural, skull vault) as pointed under the subtype V, which is found in our case.

Intradural osteomas: Report of two cases

BACKGROUND

Intradural osteoma is very rarely located in the subdural or subarachnoid space. Unfortunately, intradural osteoma lacks specificity in clinical manifestations and imaging features and there is currently no consensus on its diagnosis method or treatment strategy. Moreover, the pathogenesis of osteoma without skull structure involvement remains unclear.

CASE SUMMARY

We describe two cases of intradural osteomas located in the subdural and subarachnoid spaces, respectively. The first case involved a 47-year-old woman who presented with a 3-year history of intermittent headache and dizziness. Intraoperatively, a bony hard mass was found in the left frontal area, attached to the inner surface of the dura mater and compressing the underlying arachnoid membrane and brain. The second case involved a 56-year-old woman who had an intracranial high-density lesion isolated under the right greater wing of the sphenoid. Intraoperatively, an arachnoid-covered bony tumor was found in the sylvian fissure. The pathological diagnosis for both patients was osteoma.

CONCLUSION

Surgery and pathological examination are required for diagnosis of intradural osteomas, and craniotomy is a safe and effective treatment.

Intracranial subdural osteoma

Subdural osteomas are extremely rare benign neoplasms. Here, we report the case of a 35-year-old female patient with a right frontal and parietal subdural osteoma. The patient presented with a 2-year history of intermittent headache and fatigue. Computerized tomography (CT) scan showed a high-density lesion attached to the inner surface of the right frontal and parietal skull. Magnetic resonance imaging (MRI) demonstrated T1 hyperintensity and T2 hypointensity of the lesion. Intraoperatively, the hard mass was located in subdural space and attached to the dura mater. Histopathological examination revealed lamellated bony trabeculae lined by osteoblasts and the intertrabecular marrow spaces occupied by adipose tissue. The patient underwent neurosurgical resection and recovered without complication. Surgical excision is recommended to extract the symptomatic lesions with overlying dura mater.

Solitary subdural osteoma: A case report and literature review

BACKGROUND

Subdural osteomas are benign neoplasms that are rarely encountered. We report the case of a 64‑year‑old female patient with a left temporal subdural osteoma.

CASE DESCRIPTION

The patient presented with intermittent dizziness that first began two years earlier. Non-contrast computed tomography revealed a densely calcified left temporal extra-axial mass. Magnetic resonance imaging of the lesion revealed signal loss on T1-weighted and T2-weighted images and non-enhancement on Gadolinium enhanced T1-weighted images, and diffusion-weighted and ADC images demonstrated reduced values attributed to calcium-induced signal loss. Histologically, the lesion predominantly consisted of lamellar bone without bone marrow elements. The patient underwent stereotactic magnetic resonance imaging-guided neurosurgical resection and recovered without complication.

CONCLUSIONS

Subdural osteomas may not be enhanced on magnetic resonance imaging. Surgical tumourectomy can be considered for symptomatic patients with subdural osteomas.

Surgical case of intracranial osteoma arising from the falx

Intracranial osteomas completely unrelated to osseous tissues are extremely rare. In the present study, the case of a 40-year-old female who presented with persistent headache is reported. Computed tomography (CT) and bone window CT revealed an ossified lesion in the frontal area. Fast imaging employing steady-state acquisition (FIESTA)/CT venography fusion imaging demonstrated that the mass was located just below the superior sagittal sinus and cortical veins, and had adhered partially to these veins. Surgery achieved complete tumor removal with preservation of the cortical veins and superior sagittal sinus. The histological examination findings were compatible with osteoma. The present postoperative course was uneventful. The present rare case of intracranial osteoma originating from the falx was successfully treated surgically. Preoperative FIESTA/CT venography fusion imaging was very useful to demonstrate adhesion between the tumor mass and the superior sagittal sinus and cortical veins.

Solitary subdural osteoma: A case report and literature review

Osteomas attached to the meninges unrelated to bone are extremely rare and their etiology has not been discussed previously in the English literature. Here, we report the case of a 54-year-old male patient with a right frontal subdural osteoma. The patient presented with a ~5-month history of intermittent dizziness. Non-contrasted computerized tomography demonstrated a densely calcified mass attached to the inner surface of the right frontal skull. Magnetic resonance imaging (MRI) revealed this mass could be enhanced by contrast MRI. Intraoperatively, the hard mass was noted to be attached to the inner layer of the dura mater, and not associated with the bone. Histopathological examination revealed lamellated bony trabeculae lined by osteoblasts and the intertrabecular marrow spaces occupied by adipose tissue, which contributed to the MRI enhancement. It was speculated that subdural osteomas arose from ectopic osteoblasts derived from the embryological neural crest cells. The context of intertrabecular bone marrow contributed to the enhancement on MRI. Simple excision is the treatment of choice for symptomatic lesions.

Skull Vault Lesions: A Review

OBJECTIVE

The aim of this article is to describe the imaging features of the most common benign or malignant skull vault lesions, which may be focal, multifocal, or diffuse.

CONCLUSION

Imaging features, in association with the age, history, and clinical symptoms of the patient, make it possible to propose a course of action: simple survey, pathologic confirmation, or complete surgical resection.