BRAF-KIAA1549 fusion transcripts are less frequent in pilocytic astrocytomas diagnosed in adults

AIM

Duplication of 7q34 resulting in generation of BRAF-KIAA1549 fusion transcripts is a characteristic event in pilocytic astrocytoma that may also aid distinction from diffuse astrocytic tumours. As data on BRAF-KIAA1549 fusion transcript status remain mainly limited to children, we aimed to examine the diagnostic value of BRAF-KIAA1549 fusion transcripts across all age groups.

METHODS

BRAF-KIAA1549 fusion transcript status was examined using reverse transcription polymerase chain reaction on formalin-fixed paraffin-embedded samples of 105 primary pilocytic astrocytomas [median patient age: 17 years (1-74 years)].

RESULTS

Informative results (distinct wildtype BRAF bands detectable) were obtained in 105/124 cases (85%). Fusion transcripts were detected in 53 of cases (51%). They were more often encountered in tumours of infratentorial location [42/67 (63%) vs. 11/38 (29%)] and comprised KIAA1549-Ex16_BRAF-Ex9 (32 cases), KIAA1549-Ex15_BRAF-Ex9 (14 cases) and KIAA1549-Ex16_BRAF-Ex11 (seven cases). Fusion transcripts were present in 79% of tumours diagnosed in the first decade of life, but only in 51% of patients aged 11-20 years, 42% of patients aged 21-30 years, 30% of patients aged 31-40 years and 7% of patients older than 40 years. On multivariate logistic regression analysis, the association of fusion transcript status and age was confirmed adjusting for tumour location (P = 0.006).

CONCLUSIONS

The frequency of BRAF-KIAA1549 fusion transcripts is significantly lower in adult patients with pilocytic astrocytoma, weakening the sensitivity of this specific diagnostic marker in that age group.

The Adjustable proGAV Shunt

OBJECTIVE

To evaluate the reliability of the gravitation-assisted adjustable proGAV shunt system with a prospective multicenter study conducted in 10 German hospitals.

METHODS

Enrollment for this observational study began in April 2005 and concluded in February 2006. The protocol required re-examinations 3 and 6 months postoperatively and fixed the endpoint of follow-up at 12 months after implantation. Patients with different types of adult, juvenile, and pediatric hydrocephalus were included and 165 patients were enrolled; 9 died and 12 had incomplete follow-up.

RESULTS

Of the assessable 144 patients, 130 completed the protocol after 12 months, whereas 14 failed because of the need to explant the device, mainly because of infection. In 12 patients, components of the shunt, not the valve, were revised. In 65 of the 144 patients, there were 102 readjustments of the valve in 67 incidences because of underdrainage and in 35 because of overdrainage. In 1 case, readjustment was not possible. Determination of pressure level with the verification instrument was safe and corresponded to the required x-ray controls after adjustments. No unintended readjustments were noted.

CONCLUSION

The proGAV is a safe and reliable device.

Collision tumor of meningioma and malignant astrocytoma

The authors report a 12-year-old boy who was presented with headache, nausea, vomiting and seizure. His magnetic resonance imaging showed 2 adjacent tumors in the region of the left ventricular trigone. The pathology of tumors reported collision tumors composed of meningioma and malignant astrocytoma.

INTRANEURAL PERINEURIOMA OF THE VIIITH CRANIAL NERVE

OBJECTIVE

The authors describe the clinical and pathological features of the second reported case of an intraneural perineurioma involving a major intracranial nerve and the first case of this entity involving the VIIIth cranial nerve.

CLINICAL PRESENTATION

A 59-year-old woman presented with a long history of dizziness, tinnitus, hearing loss, and unstable gait. A magnetic resonance imaging scan revealed a small intrameatal lesion, which showed no clear progression from 2000 to 2006.

INTERVENTION

As a result of worsening symptoms and a suspected vestibular schwannoma, an attempt of tumor resection through a retrosigmoid approach was performed. This revealed diffusely infiltrated and fusiform enlarged vestibular and cochlear nerves, with no identifiable border between the main tumor mass and normal nerve. An en bloc nerve-tumor mass excision was performed. The pathological findings confirmed the diagnosis of an intraneuronal perineurioma.

CONCLUSION

The experience with this unique case and the experience of others with the management of extracranial intraneural perineuriomas lead the authors to conclude that the most reasonable surgical management of this tumor at this location is a nerve-tumor cross-section resection.

A new collagen biomatrix of equine origin versus a cadaveric dura graft for the repair of dural defects--a comparative animal experimental study

OBJECT

Numerous types of materials have been evaluated over the past decades in the quest for the ideal dural replacement, but no product fully meets all the applicable criteria. This paper presents the long-term results of an animal trial of a collagen biomatrix (TISSUDURA, Baxter AG, Vienna/Austria) for the repair and regeneration of dural defects. This product provides a matrix with a special layer structure and consists of pure naturally cross-linked collagen of equine origin. The comparable material is Tutoplast Dura, a human cadaveric-derived dural graft preserved in a multiple stage chemical process.

METHODS

Bihemispheric parietotoccipital dural defects of a defined size were induced in 25 sheep and subsequently closed with the collagen graft or Tutoplast Dura, respectively.

RESULTS

Postoperative neurological abnormalities did not occur in any animal. There were no signs of graft rejection or formation of cerebrospinal fluid fistulae. The collagen graft site displayed histological signs as early as 2 weeks postoperatively consistent with a moderate Iymphocytic inflammatory response and infiltration with fibroblasts and macrophages. The graft subsequently developed a neodura-like connective tissue architecture. The Tutoplast Dura showed only minimal cellular infiltration, and again the surrounding structures displayed a mild inflammatory response. 24 weeks postoperatively, the dura and neomembrane were barely distinguishable at the collagen biomatrix site, but the Tutoplast Dura displayed inadequate fusion with the dural border and was encapsulated in a connective tissue layer.

CONCLUSION

The outcomes demonstrate that the collagen graft can be used for dura reconstruction as a temporary dural replacement and at the same time as a biomatrix for dural regeneration.

Mikroanatomie des Sinus cavernosus

PURPOSE

The surgical anatomy of the human cavernous sinus has been described by several authors. A clearer understanding of the anatomy of the cavernous sinus has resulted in an increased interest in surgical approaches to this region. Regarding the anatomical concept of the cavernous sinus previous descriptions should be revised.

METHODS

In our study, 35 skull-base blocks including both cavernous sinuses were investigated.

RESULTS

There is considerable reason that the lateral wall of the cavernous sinus is covered by a "medial temporal dura layer" attached to the leptomeningeal pockets of the cranial nerves III-V1+2. There is no significant constance of the internal carotid artery within the cavernous sinus. All cranial nerves adjacent to or traversing the cavernous sinus are embedded within a leptomeningeal sheath similar to a pocket. The abducent nerve traverses a venous space, which should be named "petroclival venous confluence" rather than Dorello's canal. The extremely variable cavernous space is covered by a one-layer cell line. There is no evidence of any venous-plexus structure. Fibrose bands (trabecle) are present in different numbers.

Dauerhafter Erhalt der Riechnervenfunktion nach bifrontaler Kraniotomie bei Läsionen der vorderen und mittleren Schädelgrube

OBJECTIVE

The preservation of the olfactory tract during bifrontal approach for lesions located in the frontal skull base and the supra- and parasellar region has not previously been investigated.

METHODS

In our study 12 patients underwent surgery for various lesions via the basal subfrontal route. All patients were observed prospectively, olfaction testing was performed pre- and postoperatively by an independent otorhinolaryngologist.

RESULTS

We obtained complete preservation of the olfactory tracts and normal postoperative olfaction in all 12 cases.

CONCLUSION

The bifrontal approach allowed a bilateral, wide operative field with excellent orientation and views of important structures. The shortcoming of this method, damage of the olfactory tracts and postoperative anosmia can be overcome.

Taylored implants for alloplastic cranioplasty — clinical and surgical considerations

Traumatic loss of bone substance or post - decompression defects require the reconstruction of the skull. In cases of simple geometry there are handy, secure and cost effective procedures such as using autologuous cryopreserved bone flaps or polymerized Methylmethacrylat. For large sized defects CAD - taylored implants developed to provide a comfortable procedure to ensure high biocompatibility and perfect anatomical results by one - stage surgery. Furthermore cranioplasty does not only imply anatomical reconstruction but also functional recovery of awareness, cognition and motoric functions as shown in several studies according to changes in cerebral hemodynamics and metabolism. In our series of 286 patients who underwent cranioplasty during the past 10 years (1993-2003) we used taylored implants in 15 cases starting in 1999. All the patients included showed large sized defects > 64 cm2, complications did not occur neither during surgery nor the postoperative course, cosmetical results were excellent in all the patients. Neurological findings and the functional state improved in 11/15 patients, 4/15 patients showed no change, nevertheless these patients had reached a good recovery before surgery. Application of this technique is limited by cost, nonetheless it is recommended for extensive reconstruction of the skull.

Intracranial follicular dendritic cell sarcoma

✓✓ Intracranial occurrence of follicular dendritic cell (FDC) sarcoma, a rare tumor derived from dendritic cells of the lymphoid follicle, has not yet been described. Therefore, the case of a 53-year-old man presenting with an intracranial mass invading the clivus is reported. The diagnosis of FDC sarcoma was confirmed by immunohistochemical staining for dendritic cell markers, that is, CD21, CD23, and CD35. Due to some similarities with meningioma, intracranial FDC sarcoma might be an underdiagnosed disease.

The combined subtemporal-suboccipital approach: a modified surgical access to the clivus and petrous apex

OBJECTIVE

The surgical access to the clivus and the petrous apex is still a challenge. A combined approach is best fitted to lesions located in the middle and posterior cranial fossa. The approach described is centered on the petrous bone and requires an extensive bone resection; nevertheless, no osteoplastic bone flap is necessary.

METHODS

In contrast to approaches described before, the petrous bone is drilled away anterior to the sigmoid sinus more extensively, the sinus is unroofed. For exposure of the middle cranial fossa the petrous bone should be resected down to the roof of the external meatus, the total extent of the craniotomy is significantly smaller.

RESULTS AND CONCLUSION

The surgical access as described above provides a wide operative field under preservation of important intracranial structures. This modified approach minimizes the cerebellar and temporal lobe retraction. The neural and vascular structures can be preserved under direct vision to the tumor. The blood supply is interrupted at the beginning of the operation.

A new instrument facilitates the needle trephination procedure: technical note

INTRODUCTION

Percutaneous needle trephination is a well known neurosurgical procedure. The aim of this study was to develop a new instrument, which allows a stable fixation of an 18-G spinal needle in order to improve handling and precision of percutaneous needle trephinations. METHODS AND INSTRUMENTATION: The needle stabilizer was designed in a T-shape fashion morphologically similar to a corkscrew. The length of the uncovered needle tip is adjustable for individual requirements.

RESULTS

Using the new needle stabilizing device a total number of 18 percutaneous needle trephinations were performed for the following indications: subdural hematoma, epidural hygroma, bifrontal air accumulation, superficial tumor cyst, superficial brain abscess. No complications have been observed.

DISCUSSION

Our experience using this device shows that the modified technique fulfils criteria for clinical acceptance such as simplicity, low risk, reliability and cost effectiveness.

Trigeminal neuralgia caused by contralateral cerebellopontine angle meningioma - case report

A large meningioma located in the cerebellopontine angle was an unusual cause for contralateral trigeminal neuralgia. The mass effect displaced the basilar artery affecting the contralateral trigeminal nerve in vicinity of the brain stem. After radical microsurgical removal ot the tumour, the trigeminal neuralgia completely disappeared.

A cavernous hemangioma simulating an intracanalicular acoustic neurinoma--a case report

A case of an intrameatal cavernous hemangioma is reported. The 53-year-old patient presented with decreased hearing and a slight 7th nerve palsy on the left. Clinical features and preoperative radiological appearances were indistinguishable from those of an acoustic neurinoma. Though, DD the involvement of all three nerves (N. facialis, N. cochlearis, N. vestibularis) should have lead to another entity. The tumour showed intraoperatively no relationship to the 8th cranial nerve, but was very adherent to the facial nerve. The macroscopic appearance differed to the usual aspect of an acoustic neurinoma. The final diagnosis was made after the operation with histopathological methods. The clinical features and pathology of this type of tumour are discussed.

Osteoplastic lateral suboccipital approach for acoustic neuroma surgery

OBJECTIVE

Persistent headache remains a significant problem in a small group of patients after acoustic neuroma surgery via the lateral suboccipital approach. We describe a modified technique of osteoplastic lateral suboccipital craniotomy for surgery of the cerebellopontine angle. This simple and elegant technique provides a superior cosmetic result and a significant reduction in patients' symptoms.

METHODS

We report on our series of 75 patients who underwent surgery for acoustic neuroma. The maximal follow-up period was 4 years.

RESULTS

No patients reported headache postoperatively. Cerebrospinal fluid fistulae were not observed.

CONCLUSION

This modified approach minimizes cerebellar retraction, and the neural and vascular structures can be preserved under direct visualization of the tumor. This lateral suboccipital approach is a useful modification of previous approaches in acoustic neuroma surgery. It provides successful tumor resection and excellent functional results.

Cavernous angioma as a rare neuroradiologic finding in the cavernous sinus

We report the case of a 56-year-old female with a pathologically confirmed cavernous angioma of the cavernous sinus. There are only a few reports on cavernous sinus angiomas in the literature. In contrast to typical intracerebral cavernous angiomas, these lesions are characterized by strong contrast enhancement on computed tomography and magnetic resonance imaging. In spite of the problematic location within the cavernous sinus, these angiomas can be completely resected without additional neurologic deficits. The clinical course of the patient and the unusual neuroradiologic imaging findings, as well as the cases from the literature are discussed.

Preservation of the olfactory tract in bifrontal craniotomy for various lesions of the anterior cranial fossa

OBJECTIVE

Preservation of the olfactory tract during use of the bifrontal approach for the treatment of lesions located in the frontal cranial base and the supra- and parasellar regions has not been previously investigated.

METHODS

In our study, 12 patients underwent surgery, via the basal subfrontal route, for treatment of various lesions. All patients were observed prospectively, and olfactometry was performed pre- and postoperatively by an independent otorhinolaryngologist.

RESULTS

We obtained complete preservation of the olfactory tracts and normal postoperative olfaction in all 12 cases.

CONCLUSION

The bifrontal approach yields a bilateral wide operative field with excellent orientation and views of important structures. The shortcomings of this method, i.e., damage to the olfactory tracts and postoperative anosmia, can be overcome.

A craniospinal enterogenous cyst: case report

An enterogenous cyst of the craniospinal region producing medullary compression is reported in a 4.5-year-old boy. The patient presented with stiffness of the neck and headache, but otherwise without neurological deficits. Magnetic resonance imaging (MRI) demonstrated a high-intensity mass extending from the cerebellomedullary cisterna to the second cervical vertebra flattening the medulla and the upper cervical cord. Complete recovery ensued following total excision of the cyst. Histologically, the cyst was lined by a single layer of PAS-positive columnar epithelium. Presentation of this unusual case is discussed together with a review of the literature.

Analgesic effect of epidural morphine in lumbar disc surgery

In patients operated on for herniated lumbar disc, epidural morphine was administered intraoperatively at the end of the procedure. A 10 milligram dose of morphine provided significant pain relief expressed by less requirement for strong analgesics on the day of operation and the day following, as well as for sedatives during the postoperative observation period of four days in comparison to a control group of patients. The only side effect observed was urinary retention.

Surgical treatment of jugular foramen schwannomas

Sixteen patients with schwannomas of the jugular foramen were operated on in the Department of Neurosurgery of the Nordstadt Hospital in Hannover, Germany, between 1986 and 1992. Patients with neurofibromatosis were excluded. The records of the 16 patients were retrospectively reviewed. There were five women and 11 men (mean age 43 years) with a symptom duration ranging from 6 months to 20 years (mean 5 years). The predominant symptoms were hearing loss, hoarseness, and cerebellar symptoms. Computerized tomography (CT), magnetic resonance (MR) imaging, and angiography were performed in all 16 patients. Depending on the radiological and surgical features, the tumors were classified into four types: Type A, a tumor primarily at the cerebellopontine angle with minimal enlargement of the jugular foramen (eight cases); Type B, a tumor primarily at the jugular foramen with intracranial extension (two cases); Type C, a primarily extracranial tumor with extension into the jugular foramen (one case); and Type D, a dumbbell-shaped tumor with both intra- and extracranial components (five cases). A retromastoid suboccipital craniectomy was performed for Type A tumors, and a combined cervical-mastoidectomy for Types B, C, and D. Total tumor removal was achieved in all cases. There was no operative mortality. Postoperative complications were cerebrospinal fluid leakage in one patient and mastoiditis in two patients. The follow-up period ranged from 12 to 42 months (mean 22 months). All patients were alive at the last follow-up review, and CT and/or MR imaging showed no tumor recurrence.

Neuromuscular choristoma

Neuromuscular choristomas are rare, with only 13 cases having been previously reported. They usually arise in association with large nerves, and most often occur in the first decade of life. A few have been congenital. Although resection is typically curative, in two instances partial resection alone appears to have been followed by spontaneous regression. The authors report an unusual example of an otherwise classic neuromuscular choristoma where the lesion appeared to grow after incomplete initial resection. Re-excision disclosed a fibromatosis unassociated with choristoma. Despite its wide excision, a recurrence of the fibromatosis required a forequarter amputation. Theories of histogenesis and the clinicopathologic features of the neuromuscular choristomas reported to date are reviewed. The term "benign Triton tumor," although incorrectly applied to this lesion, should be reserved for benign, true nerve sheath neoplasms exhibiting myogenic differentiation.

Syringomyelia in association with tumours of the posterior fossa. Pathophysiological considerations, based on observations on three related cases

In this report we describe 3 patients with syringomyelia in association with tumours of the posterior fossa. In each patient the syrinx was demonstrated on pre-operative magnetic resonance imaging (MRI). After total or partial removal of the tumour the syrinx collapsed. It is concluded that the pathogenesis of syrinx formation in this entity requires interference with normal cerebrospinal fluid (CSF) flow at the foramen magnum. We suggest that the obstruction to the flow of CSF causes alterations in the passage of extracellular fluid (ECF) in the spinal cord which lead to syringomyelia.

Involvement of spinal nerves in neurofibromatosis

Spinal tumors are a frequent form of manifestation of neurofibromatosis. Out of 171 patients, who have been operated on over a ten years period on spinal tumors, 7 patients had neurofibromatosis (4.1%). A total of 9 operations were performed, removing 20 spinal tumors. Three patients had multiple neurofibromas. Half of the neurofibromas had a dumbbell configuration with a larger extraspinal extension. In three patients a family history of neurofibromatosis and typical dermatological signs were evident. Two cases will be selected and the basic concept regarding treatment and the risks involved will be discussed.

Management of intracavernous tumours: an 11-year experience

Seventy-one patients with tumours involving the cavernous sinus (CS) were operated upon between 1979 and 1989. Fifty-four patients underwent a direct approach to the CS. The average age of these latter patients was 47 (9-69) years. The lesions included 51 benign tumours (26 meningiomas, 16 [7 invasive] pituitary adenomas, 3 trigeminal neurinomas, one chordoma, one chondroma, one craniopharyngioma, one epidermoid tumour, and one cavernous haemangioma), and 3 malignant tumours (one chondrosarcoma, one adenoid cystic carcinoma and one metastatic adenocarcinoma). Dissecting tumour away from the carotid artery was the management of choice for intracavernous tumours which involved the internal carotid artery, except when the carotid artery had already pre-operatively presented with advanced narrowing or occlusion by encasing tumour. Microsurgical technique facilitated dissection and preservation of the cranial nerves. Patients treated radically by direct CS surgery had improvement of their symptoms and signs more frequently than those patients treated by subtotal tumour removal. However, operative complications in direct CS surgery were higher than in subtotal tumour removal without CS entry.

Cavernous angioma of the cavernous sinus: case report

An unusual case of cavernous angioma in the cavernous sinus ("cavernous cavernoma") is presented. The acute onset of symptoms simulated Tolosa-Hunt syndrome, and after neuroradiological investigations, the suspected diagnosis was an intracavernous meningioma. Macroscopical intraoperative and histopathological findings demonstrated a cavernous angioma. The lesion was completely removed from the cavernous sinus without additional neurological deficits and with improvement of the symptoms. Three additional cases in the literature are reviewed. The rarity of these lesions and the management problems related to their location in the cavernous sinus are stressed.

Cavernous Angioma of the Cavernous Sinus: Case Report

An unusual case of cavernous angioma in the cavernous sinus (“cavernous cavernoma”) is presented. The acute onset of symptoms simulated Tolosa-Hunt syndrome, and after neuroradiological investigations, the suspected diagnosis was an intracavernous meningioma. Macroscopical intraoperative and histopathological findings demonstrated a cavernous angioma. The lesion was completely removed from the cavernous sinus without additional neurological deficits and with improvement of the symptoms. Three additional cases in the literature are reviewed. The rarity of these lesions and the management problems related to their location in the cavernous sinus are stressed.

Chronic epidural hematoma--report on eight cases and review of the literature

The authors report eight cases of chronic epidural hematoma, classified according to macroscopical operative findings and histological studies of the hematomas. Clinical, radiological, and pathological findings are described. A review of 63 cases of the literature is presented, and the accepted concepts for classification and management of these lesions are discussed.

Surgical treatment of myeloradiculopathy in cervical spondylosis. A report on 438 operations

In the past eleven years we have performed 438 microsurgical ventral discectomies with bilateral foraminotomy followed by fusion with palacos in the cervical spine in our clinic. An analysis of the preoperative symptoms shows a great variability and overlapping of the various segments. To determine the right level for the operation it is crucial that the results of the clinical and the radiological examinations be evaluated. The results of ascending myelography and CT scans are of great value. In cases of cervical myelopathy a multisegmental operation is often necessary to obtain good results. The complication rate was small in our patients and a second operation was only necessary in a few cases. We had very good postoperative results in radicular pain and muscle weakness. In patients with symptoms of cervical myelopathy we achieved considerable improvement.

Surgery of petroclival meningiomas: report of 24 cases

Twenty-four patients with petroclival meningiomas were operated upon at the neurosurgical clinic of the City Hospital of Hannover between 1978 and 1987. Seventeen were women and seven men; the mean age was 45 years. Symptoms were usually present for more than 2 years before the diagnosis was made. The most common symptom was disturbance of gait; the most common preoperative sign was cranial nerve deficit, mainly of the 7th and 8th nerves. Preoperative neuroradiological evaluation included computed tomography and four-vessel cerebral angiography. Fifteen patients (62%) had a tumor larger than 2.5 cm in its major diameter. The surgical approaches used were the retromastoid, pterional, subtemporal, and combined retromastoid-subtemporal. We developed a modification of the retromastoid-subtemporal approach with preservation of the transverse sinus and used this in the last 2 patients. There was no postoperative death; 11 patients (46%) suffered postoperative complications, mainly in the form of cranial nerve deficits, often reversible. "Total" tumor removal was achieved in 17 patients (71%). Twenty patients (83%) were independent at the time of discharge from the hospital. With accurate neuroradiological evaluation, careful choice of the surgical approach, and sound application of microsurgical techniques, petroclival meningiomas may be "totally" and safely resected in a significant number of patients.