Trigeminal neurinoma presenting with intratumoral hemorrhage: report of two cases

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.

Skull base chondroid chordoma: atypical case manifesting as intratumoral hemorrhage and literature review

OBJECTIVE

Chondroid chordoma (CC) is a rare but commonest subtype of chordoma with little reported clinical information. The present study summarizes and updates present knowledge of CC.

METHODS

Literature search for demographic data and clinical appearance of cranial CCs except for those entirely confined to the sinonasal region.

RESULTS

A total of 48 English language papers published from 1968-2013 were retrieved describing 132 CCs as skull base tumors. The male-to-female ratio was 1:1. The mean age at diagnosis was 43 years, predisposing to the third to fifth decades of life. The clival (34%) and spheno-occipital (29%) regions were the most frequent sites of origin followed by the sellar (12%) and sphenoid (5%) regions. Intratumoral calcification and bony erosion were identified as the characteristic neuroimaging findings. Surgical resection by the transcranial, transsphenoidal, transnasal, transpharyngeal, or transpalatal route with or without adjuvant radiotherapy was the main treatment option. The initial treatment outcome was satisfactory in 82% of cases with considerably better prognosis compared with typical chordomas.

CONCLUSION

CC is a distinct entity to be discriminated from the typical type of chordoma. There are no distinguishing features on magnetic resonance imaging between CC and typical chordoma. Intratumoral calcification and concurrent bony erosion on neuroimaging should suggest the possibility of CC. Extensive surgical resection and adjuvant radiotherapy can achieve satisfactory outcome.

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.

Removal of cavernous malformation of the Meckel's cave by extradural pterional approach using Heros muscle dissection technique

BACKGROUND

We report on a patient with trigeminal neuralgia caused by an extraaxial cavernous malformation (CM) located within Meckel's cave. The lesion was removed via a pterional extradural approach with a modified temporalis muscle dissection technique, which was first described by Heros and Lee. Cadaveric dissections were performed to demonstrate the wider exposure gained by this approach.

METHODS

A 56-year-old man presented with a history of episodic shocklike, right-sided facial pain for 10 years. Neurologic examination revealed diminished sensation in the mandibular division of the right trigeminal nerve. Magnetic resonance imaging showed an ipsilateral enhancing lesion in Meckel's cave.

RESULTS

After placement of a lumbar drain, a right extradural pterional approach was undertaken. By reflecting the temporalis muscle posterolaterally, the craniotomy was extended so that the line of sight was level with the floor of the middle fossa. This allowed access to the lesion without needing to remove the zygoma. The lesion was resected with microsurgical technique. The patient's pain improved significantly after resection, and histopathologic examination confirmed the diagnosis of CM.

CONCLUSIONS

Extraaxial middle fossa CMs arising solely from Meckel's cave are rare. These lesions are safely and simply approached by posteriorly deflecting the temporalis muscle during a pterional craniotomy, avoiding excessive elevation of the anterior temporal lobe or further bony removal.

Giant dumbbell-shaped middle cranial fossa trigeminal schwannoma with extension to the infratemporal and posterior fossae

We present a 38-year-old female with a giant dumbbell-shaped trigeminal neurinoma originating primarily in the middle cranial fossa, extending to the infratemporal and posterior fossae through the foramen ovale and Meckel's cave, respectively. Because of the large tumour extension into the Infratemporal Fossa, a combined skull base approach (zygomatic infratemporal - transmandibular) was utilised for tumour removal, with a subsequent excellent outcome. An extensive literature review since 1935, revealed 580 cases of surgically treated trigeminal neurinomas. Among these, only three were located in three distinct compartments, making this the rarest developmental pattern for trigeminal neurinomas.

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.

Trigeminal neurinomas extending into multiple fossae: surgical methods and review of the literature

OBJECT

Since 1974, 27 patients with trigeminal neurinomas (TNs) have been treated at Keio University Hospital and ancillary institutes. In the present study the clinical features and developmental patterns of these 27 cases are analyzed, and the clinical features of 402 cases reported in the literature are reviewed. Based on the analysis of the developmental patterns of the TNs, the surgical strategy for a one-stage removal of TNs involving multiple fossae is described.

METHODS

Trigeminal neurinomas are classified into six types according to tumor location. Types M, P, and E are tumors involving a single compartment, that is, the middle fossa, posterior fossa, or extracranial space, respectively. Types MP (middle and posterior fossae), ME (middle fossa and extracranial space), or MPE (middle and posterior fossae and extracranial space) are tumors involving multiple compartments. Advances in neuroimaging technologies, such as magnetic resonance imaging, have revealed a high incidence of TNs extending into multiple fossae, namely 36.2% in cases reported since 1983 and 59% in the authors' series. All but one of the most recent 19 patients in this series underwent skull base surgery, whereas the remaining nine patients were surgically treated via the conventional subdural approach. The rate of total tumor removal and the clinical outcome were significantly better in those patients treated by skull base surgery than those treated by conventional surgery.

CONCLUSIONS

The TNs extending into multiple fossae can be totally removed using the following single-stage surgical techniques: Type MP by the anterior transpetrosal approach; Type ME by the zygomatic or orbitozygomatic infratemporal approach; and Type MPE by the zygomatic transpetrosal approach. In 12 of 13 cases involving multiple fossae in this series, total tumor removal was achieved using single-stage skull base surgery.

Vestibular schwannoma with repeated intratumoral hemorrhage

A symptomatic hemorrhage from a vestibular schwannoma is extremely rare, despite its relatively high incidence in the cerebellopontine angle. Much more unusual are repeated intratumoral hemorrhages. The authors report on such a rare case of repeated intratumoral hemorrhage from a vestibular schwannoma, presenting with sudden exacerbation of headache, nausea and vomiting. This second hemorrhage was confirmed by CT scan on the day of the onset of symptomatic exacerbation, which was 9 days after the initial CT scan, showing an enlarged amount of blood within the tumor. The MRI scan confirmed this CT finding. After removal, the tumor proved to be a typical vestibular schwannoma of mixed Antoni types A and B. Thin-dilated vessels with hemorrhage and hemosiderin-laden macrophages were observed. The patient's postoperative course was uneventful. A total of 28 reported cases of a single intratumoral hemorrhage in vestibular schwannomas, and one reported case of repeated hemorrhage are reviewed.

Frontotemporal epidural approach to trigeminal neurinomas

From 1980 through 1993 a series of 44 patients with trigeminal neurinomas was treated. Five of them were operated on for the remainder of the tumour as they had undergone previous surgery elsewhere, 35 were operated on for the first time, and 4 were not operated on for various reasons. An epidural approach to the neurinomas originating in the branches of the Vth nerve peripherally to the Gasserian ganglion (GG) was used. In the neurinomas originating in the GG or in the root of the Vth nerve, either an epidural-transdural approach or an epidural-transdural-transpetrous approach was used. All tumours operated on using the approach described in this article were completely removed. In 10 patients, the Vth nerve sensory deficits increased in comparison with preoperative deficits; in 9 their state remained unaltered; and in 11 the sensory function of the Vth nerve improved. In those patients who had experienced pre-operative atypical trigeminal pain, the pain disappeared after surgery. There was no additional treatment: radiosurgery, irradiation or chemotherapy. Histopathological examination did not reveal any malignant changes in the tumours in any of the patients. Based on our own experience and on the published data it is believed that the best treatment for trigeminal neurinomas is complete microsurgical removal of the lesion.