A combined neurilemmoma and angioma of the parasellar region. Case report

Ectopic schwannoma of the sellar region in a 1-year-old child: A case report and review of literature

Background:

Schwannomas are cranial and spinal nerves’ sheath tumors accounting for up to 8% of all intracranial neoplasms. Although typical intracranial schwannomas originate from Schwann cells surrounding cranial nerves, ectopic schwannomas are not associated with a known cranial nerve or have an unknown origin. The location of schwannomas may impose clinical challenges. Sellar region schwannomas are rare whether it is ectopic or not. Herein, we report a pediatric case of a 1-year-old female with ectopic, intra-supra sellar with a literature review. We report the first case of juvenile ectopic schwannoma in the sellar region.

Methods:

A PubMed Medline database search was performed by the following combined formula of medical subject headings (MESH) terms and keywords: ((sella turcica [MeSH Terms]) OR (sella*[Title/Abstract]) OR (ectopic [Title/Abstract]) AND ((neurilemmoma [MeSH Terms]) OR (schwannoma [Title/Abstract]) OR (neuroma [Title/Abstract]) OR (neurinoma [Title/Abstract])).

Results:

Total results of 206 articles were obtained. In exclusion of intraparenchymal and intraventricular schwannomas, only 34 articles remained. Thirty-nine cases were included in 34 articles. According to the reported cases, intrasellar schwannomas are more common in elderly individuals in an average of 49.5 years (range: 19– 79 years). They have a good prognosis and affect males to females equally (20:19).

Conclusion:

Ectopic schwannoma sited in the sellar region is rare. It is the first case to be reported in the pediatric age group with a literature review. This lesion should be highlighted and included in the differential diagnosis of sellar mass.

Reviewing Schwannoma-Hemangioma Composite Tumors With Their Tumorigenetic Molecular Pathways and Associated Syndromic Manifestations

Schwannomas are common peripheral nerve sheath tumors. Cavernous hemangiomas are vascular tumors that can affect any organ system. The coexistence of cavernous hemangioma with peripheral nervous system neoplasms is a rare occurrence. So far, 37 cases have been documented, and they have been divided into two categories: conjoined association (neoplasms discovered within the tumor tissue) and discrete association (neoplasms discovered outside the tumor tissue, thus placing neoplasms and tumors in close proximity but in different locations). Schwannomas and neurofibromas are the most prevalent tumors linked to cavernous hemangiomas that have been documented. The author provides a comprehensive review of all such cases published in the past with an emphasis on the implications of their tumorigenetic molecular pathways and syndromic manifestations.

Glioblastoma multiforme and cerebral cavernous malformations: intersection of pathophysiologic pathways

Cerebral cavernous malformations (CCM) are known to occur in both sporadic and familial forms. To date, there has been no identified association of CCM with glioblastoma multiforme. We present a 69-year-old woman with a 14 year history of multiple CCM who developed progressive aphasia. She had no radiation exposure and had only undergone a single computed tomography scan in her entire life. MRI demonstrated irregular gadolinium enhancement in the area of a prior stable CCM, suspicious for a high grade tumor. Stereotactic biopsy revealed a glioblastoma multiforme. This is a unique case of glioblastoma multiforme arising from the "site" of a known CCM. We review the literature on the genetics of cavernous malformations and propose a mechanism for the tumorigenic potential of these vascular malformations.

Development of intratumoral cyst or extratumoral arachnoid cyst in intracranial schwannomas following gamma knife radiosurgery

PURPOSE

Intracranial schwannomas presenting with cyst formation following gamma knife radiosurgery (GKRS) were investigated to clarify their clinicopathological characteristics.

METHODS

Between 1994 and 2006, 492 patients presenting with intracranial schwannomas underwent GKRS. Among them, seven cases demonstrated either new formation of cysts or enlargement of preexisting cysts, which were treated with microsurgical intervention. These cases were retrospectively reviewed with regard to neuroradiological findings and histopathology.

RESULTS

These seven cases included five vestibular and two trigeminal schwannomas. Preexisting cysts were enlarged following GKRS in three cases, while they were newly formed in four cases. Salvage microsurgery was carried out at 7-167 months after the GKRS, and subtotal resection was achieved in three, partial resection with or without cyst fenestration in four. Neurological symptoms were improved in all six symptomatic cases. Preoperative MRI demonstrated two characteristic types of cyst. One was the intratumoral type, indicating hemorrhagic change on the MRI. Histopathological analysis demonstrated a cavernous angioma within the solid compartment of tumor. These two cases demonstrated enlargement of residual tumor with new cyst formation after resection of only the cyst. The other type was extratumoral cyst, which had a structure with a thin cyst wall without contrast enhancement, and the cyst was composed of arachnoid cells without tumor cells. Extratumoral cysts enlarged despite effective control of the tumor itself, which may be caused by osmotic gradient induced by tumor degeneration following GKRS.

CONCLUSIONS

There were two types of cysts, intratumoral cyst and extratumoral arachnoid cyst, which developed following GKRS in intracranial schwannomas. Resection of the solid compartment as well as the cyst is required in schwannomas with expanding intratumoral cyst. Conversely, fenestration of the cyst alone might be effective in extratumoral arachnoid cysts.

A short illustrated review of sellar region schwannomas

INTRODUCTION

In this short illustrated review, we present the case of a frontal lobe schwannoma without cranial nerve or sellar attachment and a sellar schwannoma which mimicked a pituitary adenoma.

LITERATURE REVIEW

We review the rare occurrence of sellar region schwannomas, their clinical presentation, operative management, outcomes, and the possible pathogenesis.

ANALYSIS

The absence of Schwann cells in the central nervous system and the absence of neighboring cranial nerves in these two cases raise issues of the pathogenesis of these rare but curious lesions.

Medulloblastoma and juvenile pilocytic astrocytoma presenting as synchronous primary brain tumors in a child: case report

Multiple metastatic brain tumors and multifocal primary brain tumors of a single histological type have been published in the adult and pediatric literature. However, the simultaneous occurrence of multiple primary brain tumors with different cell types is rare. Even more rare is the pediatric presentation of multiple primary brain tumors with different cell types. The authors describe the case of an 8-year-old boy who presented with a 2-week history of progressive headache, nausea and vomiting, and imbalance. Brain MR imaging demonstrated a heterogeneously enhancing mixed solid/cystic mass of the left cerebellar hemisphere and a larger, midline, more homogeneously enhancing lesion of the superior vermis. Spinal MR imaging was unremarkable. The patient underwent a suboccipital craniotomy and subsequent gross-total resection of both mass lesions. Pathological examination revealed the left cerebellar and superior vermian lesions to be a juvenile pilocytic astrocytoma and a medulloblastoma, respectively. The patient did well in the immediate postoperative period, was discharged home, and underwent neurooncological follow-up. To the best of the authors' knowledge, they describe the first known pediatric case in which a medulloblastoma and a juvenile pilocytic astrocytoma presented as synchronous primary brain tumors. They review the literature on multiple primary brain tumors with different histological characteristics and rehash potential mechanisms for their development.

Cavernous malformation within a schwannoma: review of the literature and hypothesis of a common genetic etiology

The finding of cavernous malformations within tumors of the central or peripheral nervous system is a rare occurrence. We report a case of a histologically proven cavernous malformation found within an eighth cranial nerve schwannoma in a 76-year-old man. The patient presented with progressive loss of hearing on the left, facial pain and dysesthesia. Symptoms improved significantly after the tumor was subtotally resected through a left retrosigmoid craniotomy. Including the present report, 34 cases of cavernous malformations associated with tumors of nervous system origin, 24 cases (71%) involving tumors of Schwann cell origin, and 9 cases (26%) involving gliomas have been published. The cases were classified into two forms based on the type of association. Conjoined association, in which the cavernous malformation is located within the tissue of the nervous system tumor, and discrete association, in which the cavernous malformation and nervous system tumor are in separate locations. We explore the etiology of this association and hypothesize that a common genetic pathway may be involved in a majority of these cases.

Oligodendroglioma and juvenile pilocytic astrocytoma presenting as synchronous primary brain tumors

✓ Multiple metastatic brain tumors and multifocal primary brain tumors of a single histological type are well described in the literature. The concurrent presence of multiple primary brain tumors with different histological characteristics, however, is very rare. The authors describe the first known case in which an oligodendroglioma and a juvenile pilocytic astrocytoma (JPA) presented as synchronous primary brain tumors in the same patient.

This 43-year-old man presented with a 2-month history of progressive headaches, nausea, and vomiting. Magnetic resonance imaging demonstrated an enhancing heterogeneous right medial cerebellar lesion and a larger calcified, nonenhancing, heterogeneous right frontal lesion with surrounding edema and a mass effect. The results of a metastatic workup were unremarkable.

The patient underwent an initial right frontotemporal craniotomy and a subsequent suboccipital craniectomy 2 years later for resection of the posterior fossa lesion. Histological examination revealed the frontal and cerebellar lesions to be an oligodendroglioma and JPA, respectively. A molecular analysis detected a deletion of chromosome 1p36 in the oligodendroglioma, but not in the JPA. After the initial operation, the patient received follow-up care for his oligodendroglioma, but eventually required temozolomide for tumor progression. His condition remains stable both neurologically and according to imaging studies.

The authors describe the first known case in which a low-grade oligodendroglioma and a JPA presented as synchronous primary brain tumors. They review the literature on multiple primary brain tumors with different histological characteristics and discuss potential mechanisms for the development of these lesions.

Intrasellar Schwannomas: Report of Two Cases

OBJECTIVE AND IMPORTANCE

The complex regional anatomic features surrounding the sella turcica make the differential diagnosis of intrasellar and parasellar lesions complicated. Sellar and parasellar schwannomas are rare. With the exclusion of parasellar schwannomas arising from cranial nerves within the cavernous sinus and extending into the sella, there have been only two reported cases of true intrasellar schwannomas.

CLINICAL PRESENTATION

We describe the clinical, radiological, and pathological features of two cases in which the histopathological diagnosis of schwannoma was confirmed with immunohistochemical analyses and/or electron microscopy.

INTERVENTION

The two cases were grossly resected via a transsphenoidal approach. Follow-up monitoring revealed no evidence of recurrence.

CONCLUSION

Schwannomas may atypically occur in the sellar region, in which they demonstrate the typical light microscopic, immunohistochemical, and ultrastructural features observed in the peripheral nervous system. New and existing hypotheses regarding the histopathogenesis of intrasellar and parasellar schwannomas are presented.