Intraspinal pigmented schwannoma with malignant progression

A case with recurrent pigmented intraspinal tumour with malignant progression is presented. The primary tumour grew around the nerve roots T9 and T10, was attached to dura and infiltrated the vertebral bone tissue. On light microscopy it was comprised of monomorphic cells with large amount of cytoplasmic pigment and many large pigmented globoid bodies. Mitoses were not observed. On electron microscopy, in addition to cytoplasmic melanosomes of regular size, macromelanosomes were numerous. The tumour cells were surrounded partially by basement membrane like material. On these bases a histological diagnosis of benign pigmented tumour of neural crest origin was suggested (a possible pigmented meningioma or pigmented schwannoma). The patient got a recurrence one year after the primary operation. Biopsy from the re-operation showed histologically the same type of tumour with more pleomorphic cells. Subsequently, the tumour grew progressively and metastases were observed in the lungs and in the skin. The patient died two years after the primary operation. The malignant progression of the tumour and other reports on similar tumours was most consistent with a diagnosis of malignant pigmented schwannoma and this was confirmed later on with immunohistochemical staining showing positive staining for basement membrane components, collagen type IV and laminin as well as a positive staining for S-100 protein. The present findings show that despite benign histological features these tumours can behave very aggressively and stress the need of more information on this type of tumour.     

Simultaneous presentation of meningiomas with other intracranial tumours

Fifteen patients with simultaneous presentation of meningiomas with other intracranial tumours are reviewed. The associated tumours included a brain metastasis in six cases, glioma in three, pituitary adenoma in two, craniopharyngioma in one,acoustic schwannoma in two and brain lymphoma in one. A correct preoperative radiological diagnosis was made in 12 patients; in three others the associated tumour was discovered at operation and by histological studies. A one-stage removal of both tumours through the same approach was performed in nine patients, whereas six others underwent two-stage operations with an interval of 1 - 13 months. The literature relating to meningiomas associated with other intracranial tumours is reviewed and the possible pathogenetic correlations are discussed. A diagnostic pitfall may occur for metastasis into a meningioma, glioma surrounding a meningioma and different suprasellar lesions. The surgical indication and management of meningiomas may be significantly influenced by the presence of another different intracranial tumour.     

Simultaneously occurring tumours within the same cerebello-pontine angle: refining literature definitions and proposal for classification

We report on an unusual case of a patient, not affected by neurofibromatosis, harbouring two radiologically spatially contiguous tumours within the same cerebello-pontine angle. Pathological findings were consistent with the diagnosis of two spatially distinct primary tumours, namely a meningioma and a schwannoma. We proposed a classification of tumours occurring at the same location consistent with the different spatial arrangement and histological nature of these conditions. The correct classification of these nosological entities will allow further more accurate evaluations of these cases in order to clarify the pathogenesis, prognosis and best treatment of each one.     

Intracranial intraparenchymal schwannoma: Report of three cases

Summary Intracranial intraparenchymal schwannomas are rare. We report three patients with an intracranial intraparenchymal schwannoma and discuss the clinical and neuroradiological aspects of this particular tumour. The patients were a 21-year-old male, a 64-year-old female and a 17-year-old male. The tumours were located in cerebrum in two patients and the cerebellum in one patient. Computerized tomography (CT) scans demonstrated a slightly high density area with homogeneous enhancement by contrast medium. Magnetic resonance imaging (MRI) showed slightly low signal intensity on the T1-weighted image, high or mixed signal intensity on the T2-weighted image and homogeneous enhancement by gadolinium diethylene triamine penta-acetic acid (Gd-DTPA). Radiological studies revealed cystic components in 2 of the 3 patients. All tumours were firm, well-demarcated, and completely removed. The diagnosis of schwannoma was derived from histological and immunohistochemical studies in all 3 cases; 2 cases were also examined by electron microscopy.     

Primary pulmonary tumours of neurogenic origin.

Primary intrapulmonary neurogenic tumours are extremely rare. In a series of 1664 patients with pulmonary neoplasms observed during 1967-80 only four such tumours were identified (0.2%). All four patients underwent surgical excision. The histological diagnosis was benign neurilemmoma in three cases and malignant schwannoma in the fourth. The patients with neurilemmoma are alive and well four to 12 years after surgery, but the patient with malignant schwannoma died from metastatic spread of the tumour four months after surgery. No association with von Recklinghausen's disease was observed. Macroscopic and microscopic features generally lead to a correct diagnosis in benign types, but the histological diagnosis of malignant schwannoma may present some difficulties and requires the establishment of a definite origin in a nervous structure, identification of benign neurofibroma in different areas of the same tumour, and a high density of cells with appreciable pleomorphism, with mitosis and atypia. Benign tumours carry a good prognosis with little tendency to recur, but malignant schwannoma has a high invasive tendency and is associated with a low survival rate.     

Retro-tympanic pulsatile mass originating from dumb-bell jugular foramen schwannoma

Summary Background. Jugular foramen (JF) tumours are uncommon with paraganglioma, schwannoma and meningioma occurring most commonly in this location. JF schwannoma with extension to the retro-tympanic area has been described only once. Methods. 20-year-old man presented with headache, blurred vision, vomiting and diplopia. Findings. A left pulsatile retro-tympanic mass was seen at otoscopy. A jugular foramen tumour was found on CT and MR images. The intracranial portion of the tumour later diagnosed as schwannoma was removed. Control ENT examination confirmed that the residual retro-tympanic mass was no-longer pulsatile. Conclusions. Jugular foramen schwannomas may also extend into the retro-tympanic area. Correspondence: Bulent Bakar, M.D., Department of Neurosurgery, MESA Hospital, Yasam Caddesi No: 5, 06510 Sogutozu, Ankara, Turkey     

Production of Urokinase-Type Plasminogen Activator (u-PA) and Plasminogen Activator Inhibitor-1 (PAI-1) in Human Brain Tumours

Summary We investigated the role of plasminogen activators (PAs) and their inhibitor (plasminogen activator inhibitor-1, PAI-1) in human brain tumours. The amounts of urokinase-type plasminogen activator (u-PA), tissue-type plasminogen activator (t-PA), and plasminogen activator inhibitor-1 (PAI-1), and the activity of u-PA and t-PA were determined by enzyme-linked immunosorbent assay (ELISA), and u-PA and PAI-1 were immunolocalized using monoclonal antibodies in human brain tumours and normal brain tissues. The tissues were surgically removed from 64 patients; normal brain tissue (5 cases), low-grade glioma (4 cases), high-grade glioma (17 cases), metastatic tumour (9 cases), meningioma (benign 12 cases, malignant 6 cases), acoustic schwannoma (11 cases). u-PA activity and u-PA and PAI-1 antigen levels were significantly elevated in malignant brain tumours (malignant meningiomas, high-grade gliomas, and metastatic tumours) and acoustic schwannomas but very low in benign meningiomas, low-grade gliomas and normal brain. There was no difference in t-PA antigen levels among normal and malignant tissues, however levels of t-PA activity were markedly decreased in metastastic tumours. All malignant brain tumour tissues showed positive immunostaining for u-PA and PAI-1, however, some tumour cells showed negative intensity while others showed strong intensity for these antibodies. This contrasts to the homogeneous staining pattern found in acoustic schwannoma. These findings indicate that malignancy in human brain tumours is associated with elevated levels of u-PA and PAI-1 and that an imbalance between these proteins in a micro-enviroment contributes (ascribes) to tumour cell invasion.     

Evaluation of brain tumour laser surgery

Summary A surgical carbon dioxide laser unit (laser) has been used since 1977 in twentyfive cases of various brain tumours, including ten meningiomas (four sphenoid ridge, two parasagittal, two falx, one olfactory, one posterior fossa), eleven gliomas (seven glioblastoma, four astrocytoma), two metastatic brain tumours, one haemangioblastoma, and one arteriovenous malformation (AVM).The criteria for laser use, as based on evaluation and location of meningioma, were: grade 1, convenient but adjuvant; grade 2, also necessary; grade 3, indispensable. The laser is obligatory in sphenoid ridge meningioma in order to peel the tumour away from the internal carotid artery, middle cerebral artery, cavernous sinus etc. The grade of necessity for laser use is therefore either 2 or 3. In convexity or parasagittal meningioma, on the other hand, the necessity grade is either 1 or 2.In the glioma group hemorrhage in seven cases of glioblastoma was easily laser-controlled, and the tumours were wasted away in a short time through vaporization, with minimum mechanical effect on adjacent tissue. The laser is therefore very useful in cases of glioma, especially glioblastoma, considering the shortened operating time, decreased blood loss, and extended area of tumour resection.Laser surgery is proposed as being most appropriate, mainly for its vaporizing and coagulating functions, in cases of brain tumour involving the elderly and poor risk cases.     

Rapid enlargement of a vestibular schwannoma following gamma knife treatment.

Stereotactic radiosurgery has been proposed as the first line treatment for acoustic tumours and has been particularly advocated in cases of Type 2 Neurofibromatosis (NF2) with bilateral acoustic nerve tumours. We present the case of a 22-year-old male with NF2 and bilateral acoustic nerve tumours. He underwent an uncomplicated excision of the larger, left sided lesion. Histology showed a benign acoustic schwannoma with no atypical features. One year later he underwent stereotactic radiosurgery (Gamma Knife 1500 cGy) to the right sided lesion. After initial swelling, within 12 months the tumour had reduced in size and undergone central necrosis. However, 2 years later MRI of the brain revealed a dramatic increase in the size of the right sided tumour, with considerable brain stem compression. The patient subsequently died. This highly unusual case highlights the need for careful clinical and radiological follow up. in patients with acoustic tumours, regardless of the treatment method employed.     

Fatal delayed post-operative cerebral venous thrombosis after excision of hypoglossal nerve schwannoma

Lower cranial nerve schwannomas are rare tumours. We present a 35 year old female patient who had a lower cranial nerve schwannoma with both intracranial and extracranial components. The internal jugular vein was injured during the dissection of the extracranial portion of the tumour. Ligation of the internal jugular vein is not associated with significant post-operative complications. Our patient however, developed retrograde cortical venous thrombosis on the 14(th) post-operative day resulting in multiple areas of haemorrhagic venous infarction with raised intracranial pressure. Such a delayed contiguous cortical venous thrombosis has not been reported. We present this report to highlight this event and to outline the probable causes for the same.     

High dose radiation induced meningioma

Radiation therapy has played an important integral part in the management of various intracranial rumours. However, radiation has been implicated in the development of intracranial tumours. We describe three cases of radiation-induced meningiomas following high dose cranial irradiation. All these patients developed tumours within the previous radiation field and satisfied the criteria used for the definition of radiation-induced neoplasm. The interval between the irradiation and the onset of meningioma was significantly less in the younger patient. All the cases had several unique features of radiation-induced meningioma including features of atypical meningioma. Two patients developed multiple site meningiomas and one patient developed early recurrence of the tumour. This report confirms that patients exposed to cranial irradiation are at lifelong risk of developing radiation-induced tumours such as meningiomas. Hence these patients require long-term clinical and radiological surveillance to detect occurrence as early as possible.     

Endoscopic endonasal extended transsphenoidal removal of tuberculum sellae meningioma (TSM): an experience of six cases

Abstract Aims. Tuberculum sellae meningiomas (TSMs) are usually removed through a transcranial approach. Recently, the sublabial transsphenoidal microscopic approach has been used to remove such tumours. More recently, endonasal extended transsphenoidal approach is getting popular for removal of tuberculum sellae meningioma. Here, we describe our initial experience of endonasal extended transsphenoidal approach for removal of suprasellar meningiomas in six consecutive cases. Materials and method. Six patients (four female and two male) who presented for headache and visual loss were investigated with MRI of brain that showed tuberculum sellae meningioma compressing visual apparatus. Average size was 3 × 3 cm in three cases and 4 × 4 cm in rest of the three. All patients underwent endoscopic endonasal extended transsphenoidal tumour removal, but in two patients with large tumour, microscopic assistance was needed. Complete tumour removal was done in all cases except one case where perforators seemed to be encased by the tumour and resulted in incomplete removal. The surgical dural and bony defects were repaired in all patients with thigh fat graft. Nasal packing was not used, but inflated balloon of Foley's catheter was used to keep fat in position. Result. There was mild postoperative cerebrospinal fluid (CSF) leakage in one patient on the fourth postoperative day after removal of lumbar CSF drain and stopped spontaneously on the seventh postoperative day. There were no postoperative CSF leaks or meningitis in the rest of the cases. In one patient, there was visual deterioration due to pressure on optic nerve by grafted fat and improved within 4 weeks. At 4 months after surgery, three patients had normal vision, two patients improved vision comparing with that of preoperative state but with some persisting deficit; one patient had static vision, no new endocrinopathy and no residual tumour on MRI in five cases but residual tumour in remaining case was static at the end of the ninth month. Conclusion. The endoscopic endonasal extended transsphenoidal approach appears to be an effective minimally invasive method for removing relatively small to medium tuberculum sellae meningiomas. With more experience of the surgeon, larger tuberculum sellae meningioma may be removed by purely endoscopic techniques in near future.     

Treatment of orbital schwannomas and neurofibromas

We present an overview of the treatment and clinical outcome of five orbital peripheral nerve tumours, carried out in our centre from 1999 to 2003. The surgical approach was determined by the location and extension of the lesion. Supraorbital orbitotomy was performed in two superiorly located lesions, a transconjunctival approach in one medial, basal, extraconal lesion. A pterional extradural approach was used in two cases with involvement of the apex, superior orbital fissure and cavernous sinus. Three patients were diagnosed as having schwannoma, one as neurofibroma, and one as cystic mixed neurofibroma and schwannoma. One patient suffered from multiple schwannomas [bilateral acoustic schwannomas, cervical schwannomas (NF2)]. One patient showed bilateral orbital neurofibromas, plexiform cutaneous neurofibroma (NF1) and glaucoma due to a coexisting Marfan's syndrome. Local recurrences were not seen after complete resection in all patients. Surgery is the therapeutic goal.     

RETROPERITONEAL SCHWANNOMA: A CASE SERIES AND REVIEW

Schwannomas account for only a small percentage of retroperitoneal tumours. Presentation is typically varied and non-specific and pre-operative diagnosis is difficult. Herein are described five cases of retroperitoneal schwannoma. Presentation was varied, ranging from abdominal pain, abdominal mass, obstructed labour or an incidental finding. All patients had either an abdominal computed tomography scan and/or ultrasound performed. Pre-operative biopsy either by fine needle aspiration (in one patient) or core biopsy in two patients was unhelpful. In four patients with smaller tumours, complete excision was possible with no apparent long-term morbidity and no clinical evidence of recurrent tumour with follow up from 3.5 months to 11 years. For the largest tumour, complete surgical excision was not attempted as it would have entailed significant morbidity.     

Cytotoxic immune response of meningioma patients towards allogeneic and autologous tumour cells before and after surgery

Summary Cell-mediated cytotoxicity (CTX) of meningioma patients towards meningioma cells and fibroblasts was studied in vitro before and after surgery, using the³H-proline microcytotoxicity test. When incubated with allogeneic target cells before surgery, lymphocytes from three out of seven donors showed a specific destruction of meningioma tissue, and two were cytotoxic on both types of targets. Five patients were tested against their own tumour and against skin fibroblasts; this was feasible by keeping their lymphocytes frozen in liquid nitrogen until their target cells grew as suitable monolayers in vitro. Three patients showed a specific cytotoxic response. After excision of the tumour a gradual loss of this reactivity was observed in both allogeneic and autologous systems.Sera of three patients, whose lymphocytes were not reactive against their own tumour, induced antibody-dependent cellular cytotoxicity (ADCC) towards autologous tumours if normal effector cells were used. This type of response was detectable mainly in postoperative sera, and could not be elicited in autologous lymphocytes. On the contrary, autologous sera inhibited CTX of meningioma effector cells.The data suggest that meningiomas can induce a complex immunological response in the host, which is dependent on the presence or absence of a large tumour burden.     

Intrameatal Tumours Presenting as a Hearing Disturbance: Case Reports of Meningioma and Lymphoma

Summary  This paper presents two patients with chronic progressive hearing disturbance. Each patient had an intrameatal tumour, part of which extended to the cerebellopontine (CP) angle. In both cases, the patients were initially diagnosed with an acoustic neurinoma. A 63-year-old male experienced a hearing disturbance in the left ear for 1.5 years prior to visiting our hospital. Magnetic resonance (MR) imaging revealed a mass which was surgically resected. The tumour originated from the intrameatal dura mater. Histologically, the tumour was a meningioma. Similarly, a 53-year-old male presented with systemic lymphoma diagnosed 10 months earlier, and a hearing disturbance in the right ear that began 3 months prior to visiting our hospital. MR imaging prior to chemotherapy revealed a mass which extended to the CP angle. Part of the tumour in the CP angle disappeared after chemotherapy, suggesting a secondary lymphoma. Another tumour appeared later in Meckel's cave on the left side; however, it decreased in size following repeated chemotherapy. The present results indicate that differential diagnosis of intrameatal tumours and acoustic neurinomas may be difficult due to the small tumour size. Recent progress in neuroradiology may allow distinction of intrameatal tumours as a separate tumour classification. Our second patient is the sixth reported case of a CP angle lymphoma in the literature.     

Primary benign mesenteric schwannoma

Schwannomas, also known as neurilemmomas, are benign tumours arising from the sheath of peripheral nerves in the soft tissues of head, neck, extremities, mediastinum and retroperitoneum. Schwannomas are relatively slow-growing and mostly benign. Primary mesenteric schwannoma is extremely rare. In this report, we describe a 45-year-old female who presented with a lump in the abdomen caused by a benign schwannoma originating from the mesentery of the small bowel, which was treated with surgical resection and marsupialization of the remnant capsule on the posterior side. A high grade of suspicion is required to diagnose such a tumour. Ultrasonography is generally inconclusive, but histopathological examination can confirm diagnosis. The patient was followed up for six months without evidence of disease recurrence.     

Meningiomas: Correlation between MRI characteristics and operative findings including consistency

Summary The findings on magnetic resonance imaging (MRI) in 73 surgically verified intracranial meningiomas were correlated with their histology and consistency during resection.T 1-weighted imaging was least useful since most of the tumours were iso-intense, similar to cortical grey matter regardless of histology or tumour consistency. The signal intensity on T 2-weighted images was found to best correlate with both the histology and consistency of the meningioma. Generally, the low intensity portion of the tumour on T 2-weighted images indicated a more fibrous and harder character, while the higher intensity portions indicated a more soft character. Most of the fibroblastic meningiomas showed the features of a hard tumour while angioblastic tumours showed the features of soft tumours.Tumours predicted to be harder on MR imaging generally took longer to resect than softer ones, and this relationship was shown best for the larger tumours. Using linear regression analysis, it appears that operative time for soft tumours is more affected by factors other than tumour consistency. Blood loss during surgery was also unrelated to the consistency of the tumour.These results suggest that the histology and consistency of meningiomas may be predictable from findings on T 2-weighted imaging, and this may also predict the difficulty and time required for resection.     

Gamma-knife radiosurgery in the treatment of trigeminal schwannomas

Summary Background. Trigeminal nerve schwannomas account for 0.07%–0.28% of all intracranial tumours. Advances in skull base surgery have led to more aggressive resection of these tumours, but surgery may associated with development of new neurological deficits. Methods. In this report, we analyse the long-term results 15 patients with newly diagnosed or residual/recurrent trigeminal schwannoma who underwent gamma-knife treatment. Findings. During a mean 61 months of follow-up, MRI revealed reduction of tumour size in 13 and no size change in 2 patients. The tumour growth control rate was 100% and only 1 patient had transient facial numbness and diplopia. Conclusions. For patients with small to moderate size trigeminal schwannomas, gamma-knife radiosurgery is associated with good tumour control and a minimal risk of adverse radiation effects.