Basioccipital bone osteochondroma growing into the foramen magnum

Intracranial osteochondroma arising from the posterior clinoid process: a rare case report with diagnostic challenges and comprehensive literature review

Introduction and importance

Intracranial osteochondroma is rare, presenting diagnostic challenges due to overlapping imaging findings with other pathologies. This case report highlights the significance of considering osteochondroma in calcified tumour differentials near bone.

Case presentation

A 34-year-old man with vision deterioration and headaches had an MRI revealing a suprasellar lesion. Intraoperatively, a bony hard tumour was partially resected. Subsequent computed tomography (CT) confirmed a calcified mass contiguous with the posterior clinoid.

Clinical discussion

Reviewing 28 cases, skull base osteochondromas were common, with differential diagnoses including craniopharyngioma and meningioma. Surgical decision-making involved balancing complete resection for convexity and falx cases versus partial resection for skull base tumours due to proximity to critical structures.

Conclusion

Intracranial osteochondroma poses diagnostic challenges, especially near bone. Tailored surgical approaches are vital, with complete resection yielding good outcomes for convexity and falx cases. Close follow-up is crucial for monitoring recurrences and complications.

Surgical Strategies and Outcomes for Intracranial Chondromas: A Retrospective Study of 17 Cases and Systematic Review

Objective

To improve the diagnosis and treatment of intracranial chondromas (ICDs) by discussing the clinical manifestations and imaging characteristics of ICDs, as well as surgical methods and treatment strategies.

Methods

We retrospectively analyzed 17 patients diagnosed with ICDs who underwent microsurgery or endoscopic transsphenoidal surgery at the Tangdu Hospital of Air Force Military Medical University and the Mianyang Central Hospital from January 2010 to November 2021. Clinical manifestations, imaging examinations, surgical treatments, and prognosis of these patients were analyzed.

Results

ICDs had often been misdiagnosed as craniopharyngioma, chordoma, schwannoma, cavernous hemangioma, pituitary adenoma, and meningioma before surgery. Of the 17 cases, gross total resection (GTR) was performed in 10 cases, subtotal resection (STR) in 5, and partial resection in 2. GTR of tumor was achieved in eight cases via the endoscopic endonasal transsphenoidal approach (EETA) or the extended endoscopic endonasal transsphenoidal approach (EEETA), and the remaining patients underwent craniotomies. Clinical symptoms were assessed 1 week after surgery, 10 cases were relieved at varying degrees, and four cases had no improvement. Postoperative complications included right-limb hemiparesis, diplopia, eyelid ptosis, pulmonary infection, subcutaneous hydrops, cerebrospinal-fluid leakage (CSFL), and intracranial infection (ICI). One patient received gamma knife treatment at 3 months after surgery, two patients died due to tumor progression, and the remaining patients had no tumor recurrence.

Conclusions

ICDs lack typical imaging features and are often misdiagnosed. The EETA or EEETA helps improve the surgical outcomes and GTR rates of ICDs at different sites.

Foramen magnum osteochondroma causing myelopathy in a patient with hereditary multiple exostoses

Background:

Osteochondromas are commonly occurring benign bone tumors which may be either a solitary lesion or occur due to association with hereditary multiple exostoses (HMEs). There have been several reported cases of spinal osteochondromas, but intracranial lesions are rare.

Case Description:

A 51-year-old male with a history of multiple osteochondromas presented with myelopathy. He had an exostosis arising from the foramen magnum causing compression of the cervical spinal cord that was successfully removed. Genetic testing revealed that he had HMEs.

Conclusion:

Osteochondromas of the skull are extremely rare. However, parts of the foramen magnum ossify in cartilage and can give rise to an osteochondroma. Here, we present a patient with HMEs who developed cervical myelopathy due to an osteochondroma arising from the foramen magnum. Due to the cartilaginous ossification of the foramen magnum, clinicians should be aware that osteochondromas can occur in this location and potentially give rise to cervical myelopathy.

Cranial Nerve Foramina: Part II - A Review of the Anatomy and Pathology of Cranial Nerve Foramina of the Posterior Cranial Fossa

Cranial nerve foramina are integral exits from the confines of the skull. Despite their significance in cranial nerve pathologies, there has been no comprehensive anatomical review of these structures. Owing to the extensive nature of this topic we have divided our review into two parts; Part II, presented here, focuses on the foramina of the posterior cranial fossa and discusses each foramen's shape, orientation, size, surrounding structures, and structures that pass through it. Furthermore, by comparing foramen sizes against the cross-sectional areas of their contents, we determine the amount of free space available within each. We also review lesions that can obstruct each foramen and discuss the clinical consequences.

A multidisciplinary approach for the treatment of young patients with suprasellar osteochondroma

BACKGROUND

Osteochondroma is the most common benign bone tumor; intracranial osteochondroma is a very rare finding in the neurosurgical literature and most of them arise from the skull base.

CASE REPORT

We report a case of suprasellar ostheocondroma in a 16-year-old female, with its CT and MRI appearances, which caused visual deficits, resolved after surgery.

DISCUSSION

To our knowledge, this is the fifth case of osteochondroma affecting the suprasellar region that has been reported, with all the characteristic features of this tumor: optic chiasmal syndrome, intralesional calcifications, cartilage cap, and contrast enhancement.

CONCLUSION

Multidiscplinary teams, including a neuro-ophthalmologist, endocrinologist, neuroradiologist, neurosurgeon, and neuropathologist are needed for correct treatment of the disease and appropriate follow-up.

Joint Capsule-Like Intracranial Osteochondroma Mimicking Cystic Meningioma

This report provides the first representative images of an intracranial osteochondroma with a cystic component mimicking cystic meningioma. A 40-year-old male presented at our outpatient clinic with decreased sensation in his right upper extremity. Preoperative computed tomography showed a tumor with a cystic meningioma-like appearance and prominent calcifications. On magnetic resonance imaging, calcification of the lesion was suggested by the T2-weighted image; weak enhancement was seen on the T1-weighted image. Following surgical removal of the tumor, the pathologic examination showed findings consistent with osteochondroma. Cystic meningioma is a rare tumor with a cystic component. Intracranial osteochondroma is also a rare, benign tumor that can mimic meningioma when presenting in the dural convexity. Our report describes the joint capsule-like appearance of a convex cystic osteochondroma including a calcified cap, bonelike structure, and fluid-containing intracapsular space. The tumor was evaluated by imaging and pathologic studies.

Solitary Osteochondroma of the Skull Base: A Case Report and Literature Review

We report a case of an osteochondroma in the posterior clinoid process that occurred in a 43-year-old man with trochlear nerve palsy. Although the potential preoperative diagnoses based on computed tomography and magnetic resonance imaging included other intracranial tumors such as calcified meningioma, thallium-201 single-photon emission computed tomography effectively differentiated osteochondroma from those possibilities. Via an orbitozygomatic approach, a subtotal resection was achieved with a good relief of symptoms. Twenty-two cases of solitary osteochondromas in the skull base have been reported that have demonstrated little risk of recurrence or malignant transformation. However, surgery for skull base osteochondromas does carry a significant risk with a reported mortality > 10%. Although some previous reports advocate complete resection as the only curative method for skull base osteochondromas, the risks of total resection should be weighed against the chance for recurrence; our review of the literature demonstrated a relatively high mortality and an extremely low incidence of recurrence.

Meningeal osteochondroma simulating meningioma with metaplastic change: a rare golf-ball-like lesion of non-meningothelial mesenchymal origin

Non-meningothelial mesenchymal tumors of the central nervous system (CNS), including those originating from the meninges, histologically correspond to tumors of soft tissue or bone. These individual entities arising from the meninges are rare, and probably have their origin in the multipotent primitive mesenchymal stem cells of the dura. Though it is a common bone tumor, the meningeal origin of osteochondroma has only very rarely been reported. We describe a case of a 35-year-old female with a well-demarcated, golf-ball-like osteochondroma of meningeal origin which was enucleated en bloc on craniotomy. Such a lesion can resemble a meningioma that exhibits metaplastic (osseous) change on imaging. However, provided that there is clinico-radiological awareness of such tumors, magnetic resonance imaging (MRI) can guide the way to this rare differential diagnosis, as it reflects the pathologic appearance of osteochondroma and allows the thickness of the cartilage cap to be estimated in order to check for rare malignant change. Complete excision along with the cartilage cap usually offers a favorable prognosis without recurrence.