枕骨大孔区肿瘤的显微外科治疗

目的 探索枕骨大孔区肿瘤的治疗方法以提高治疗效果。方法 通过显微外科手术治疗31例枕骨大孔区肿瘤,其中脑膜瘤13例,神经鞘瘤15例,脊索3例。根据肿瘤附着点、生长方式及手术入路将肿瘤分为2种类型：I型：肿瘤主要位于枕骨大孔前方,包括基底起源于枕骨大孔上方、前方和前侧方,共15例;Ⅱ型：肿瘤主要位于枕骨大孔后方,包括基底起源于枕骨大孔后方、后侧方和椎管内,共16例。采用3种手术入路切除肿瘤：枕颈后正中和侧方入路18例,远外侧或经髁入路10例,枕下乙状窦后入路3例。结果 肿瘤全部切除25例,次全切除5例,部分切除1例,无手术死亡。I型枕骨大孔区肿瘤全切除9例,次全切除5例,部分切除1例;Ⅱ型均全切除。结论 I型枕骨大孔区肿瘤,手术全切除肿瘤困难,远外侧经髁入路是切除I型枕骨大孔区肿瘤最有效的方法;Ⅱ型肿瘤容易全切除,预后良好。     

Craniopharyngioma extended into the posterior fossa

A 7-year-old girl with a craniopharyngioma with a rare extension into the posterior fossa is presented. MRI revealed a solid calcified mass in the sellar and suprasellar region with a cyst expanded to the posterior fossa up to the foramen magnum and causing hydrocephalus and brainstem displacement. The tumor was removed totally with right pterional approach.     

Analysis of the posterior fossa in children with the Chiari 0 malformation

OBJECTIVE: We previously reported the resolution of syringohydromyelia without cerebellar tonsillar ectopia in five patients after posterior fossa decompression of the so-called Chiari 0 malformation. A sixth patient is described. In this study, the anatomy of the posterior fossa is analyzed using radiological imaging, enabling features of the posterior fossa in this uncommon subgroup of children to be characterized. METHODS : Multiple measurements were made on magnetic resonance imaging studies in six children with Chiari 0 malformation to determine the position of the brainstem relative to the foramen magnum. Fifty children with normal magnetic resonance imaging studies of the brain were used as controls. RESULTS: All children with a Chiari 0 malformation were found to have the following positive results: obices that were located more than 2 standard deviations below normal, an increase in the anteroposterior midsagittal distance of the spinomedullary junction at the level of the foramen magnum, an increase in the angle between the floor of the fourth ventricle and clivus, and an increase in the anteroposterior midsagittal distance of the foramen magnum. CONCLUSION: The findings of this study suggest that the contents of the posterior fossa are indeed compromised and/or distorted in patients with syringohydromyelia but no tonsillar ectopia. In this group, the brainstem was caudally displaced more than 3 standard deviations below normal.     

Foramen magnum meningioma and arachnoid cyst coinciding in the lateral cerebellomedullary cistern--case report.

An extremely rare foramen magnum meningioma associated with an arachnoid cyst in the lateral cerebellomedullary cistern occurred in a 65-year-old female presenting with dizziness. Neuroimaging revealed a meningioma at the left lateral edge of the foramen magnum and an arachnoid cyst mainly located in the right lateral cerebellomedullary cistern, compressing the medulla oblongata bilaterally. After fenestration of the cyst wall and tumor removal, the clinical symptoms ameliorated. We recommend that where a foramen magnum tumor coexists with an arachnoid cyst of the posterior fossa, the tumor should be removed after shrinking the cyst to obviate the need for brainstem retraction.     

Surgical approach for hypoglossal schwannomas to prevent deformity of the atlanto-occipital joint

Background  Hypoglossal schwannomas are very rare tumors that often enlarge the hypoglossal canal and jugular foramen, and erode the bone bridge of the occipital condyle. We compared pre- and postoperative 3D bone CT images and discussed the ideal craniotomy to prevent fracture formation. Method  Seven patients with hypoglossal schwannomas underwent surgery in our department. Six cases were type B and 1 case was type C. All patients complained of hypoglossal nerve paresis and nuchal pain. Findings  We used the condylar fossa approach for four cases of type B, the lateral suboccipital approach with C1 laminectomy for two cases of type B and extradural transjugular approach for one case of type C. In all cases, the lateral rim of the foramen magnum or the posterior rim of the jugular foramen was not resected at the same time. The intracranial part of the tumor was removed in all type B cases. Radiotherapy was added for the residual tumor. No patient had deformity or fracture of the joint. Conclusions  Opening the hypoglossal canal and dural incision toward the hypoglossal canal are important for high radicality. However, preservation of the lateral rim of the foramen magnum must be noted to prevent consecutive deformity or fracture of the atlanto-occipital joint.     

Surgical management of ventral and ventrolateral foramen magnum meningiomas: report on a 64-case series and review of the literature

Foramen magnum meningioma poses a challenge for neurosurgeons. Prognosis has generally improved with diagnostic and surgical advances over the past two decades; however, it may ultimately depend more on the surgeon's ability to tailor the approach and interpret intraoperative risks in single cases. The series comprised 64 patients operated on for ventral and ventrolateral foramen magnum meningioma. All patients underwent preoperative magnetic resonance imaging and received surgery via the dorsolateral route, rendering the series homogeneous in neuroradiological workup and surgical treatment. Particular to this series was that the majority of patients were of advanced age (n?=?29; age, >65 years), had serious functional impairment (n?=?30, Karnofski score <70), and large tumors (mean diameter, 3.5 cm). Total tumor removal was achieved in 52 (81 %) patients; operative mortality was nil. Early outcome varied depending on difficulties encountered at surgery (cranial nerve position and type of involvement in particular) and type of preoperative dysfunction. Long-tract signs and cerebellar deficits improved in 74 and 77 % of cases, respectively, but only 27 % of cranial nerve deficits did so. Surgical complications most often involved the cranial nerves: cranial nerve impairment, especially of the 9th through the 12th cranial nerves, due to stretching or encasement was noted in 44 cases. At final outcome assessment, two thirds of the cranial nerve deficits cleared, and all but two patients returned to a normal productive life. One patient was reoperated on during the follow-up period. Foramen magnum meningiomas behave like clival or spinal tumors depending on their prevalent extension. A dorsolateral approach tailored to tumor position and extension and meticulous surgical technique allow for definitive control of surgical complications. Scrupulous postoperative care may prevent dysphagia, a major persistent complication of surgery. Long-term observation of indolent tumor behavior at follow-up suggests that incomplete resection may be a viable surgical treatment option.     

Surgical approaches to foramen magnum meningioma--report of three cases.

Although foramen magnum meningiomas are usually removable, their location poses considerable surgical risk. The authors present three cases of foramen magnum meningioma. The first involved a ventral type tumor extending to the second cervical body. Following bilateral mandibulotomy, surgery was performed via the anterior transoral approach and the tumor was totally removed. Nine days postoperatively, she developed meningitis, which was successfully treated with antibiotics. The second patient's tumor was dorsal type and was deeply embedded in the lateral part of the vermis. The tumor was totally removed via the midline suboccipital approach and she recovered uneventfully, with only slight upper-extremity paresthesia. In the third case, the tumor was ventral type and situated mainly in the clivus. Craniotomy was performed by the bilateral suboccipital approach and extended nearly to the jugular tubercle. The tumor, which severely displaced the lower cranial and upper cervical nerves, was totally removed. The postoperative course was lengthy and complicated. Artificial ventilation was required for 2 months, and difficulty in swallowing persisted during long-term follow-up. As illustrated by the second case, dorsal and lateral type foramen magnum meningiomas can usually be removed via the lateral suboccipital approach. In the case of ventral type tumors, the anterior transoral approach entails the risk of infection, as occurred in the first case. The authors conclude that the lateral suboccipital approach is preferable; craniotomy extending to the jugular tubercle lowers the risk of brainstem damage.     

Surgical experience with skull base approaches for foramen magnum meningioma

The surgical treatment of patients with foramen magnum meningioma remains challenging. This study evaluated the outcome of this tumor according to the evolution of surgical approaches during the last 29 years. A retrospective analysis of medical records, operative notes, and neuroimages of 492 meningioma cases from 1972 to 2001 identified seven cases of foramen magnum meningioma (1.4%). All patients showed various neurological symptoms corresponding with foramen magnum syndrome. The tumor locations were anterior in five cases and posterior in two. Surgical removal was performed through a transoral approach in one patient, the suboccipital approach in three, and the transcondylar approach in two. Total removal was achieved in all patients, except for one who refused any surgical treatment. The major complications were tetraparesis and lower cranial nerve paresis for tumors in anterior locations, and minor complications for posterior locations. One patient died of atelectasis and pneumonia after a long hospitalization. The transcondylar approach is recommended for anterior locations, and the standard suboccipital approach for posterior locations.     

Surgery for Syringomyelia: An Analysis Based on 163 Surgical Cases

Summary ? Object. The authors analyzed the cases of 163 patients with syringomyelia to assess the appropriate surgical procedure. Methods. Depending on the aetiological factors and treatment considerations the series was classified into three groups. Group I were cases where there was no definite demonstrable aetiological factor; Group II cases had basilar invagination and/or Chiari malformation; and Group III consisted of cases where the syrinx was secondary to an obvious aetiology, such as a mass lesion either in the posterior cranial fossa or in the spine or a severe kyphotic spinal deformity. Post-traumatic syringomyelia and syrinx in association with spina bifida were not studied. Conclusions. We concluded that for Group I cases syringosubarachnoid shunting is the ideal form of treatment. In Group II cases foramen magnum bony decompression is satisfactory and physiological. Good results were obtained even in cases where either a foramen magnum decompression alone or in combination with a syringo-subarachnoid shunt was done. Only syringosubarachnoid shunt (without a foramen magnum decompression) in Group II cases was found to produce poor outcome. Group III cases should be treated for the primary aetiological problem. Only syrinx drainage procedure without treatment of aetiology in these cases produced poor results. It was observed that clinical outcome rather than radiological improvement is the reliable indicator of the surgical result.     

Peritumoral brain edema in intracranial meningiomas: effects of radiological and histological factors

OBJECTIVE: We examined the radiological and histological features influencing the development of peritumoral brain edema (PTBE) among patients with meningiomas. METHODS: Factors causing PTBE were retrospectively analyzed for 125 patients with primary intracranial meningiomas. These factors included tumor size, tumor location, brain-tumor interface, signal intensity on T2-weighted scans, contrast enhancement, and cyst formation (as observed on magnetic resonance imaging scans), as well as tumor vascularity and blood supply (as observed in digital subtraction angiography studies). We defined the edema/tumor volume ratio as the edema index, and we used this index to evaluate PTBE. RESULTS: A relationship between the tumor size and the volume of PTBE was observed. Convexity and middle fossa meningiomas demonstrated the greatest increases in mean edema indices. Meningothelial, anaplastic, microcystic, and angiomatous subtypes exhibited higher edema indices than did other types. Multivariate analysis demonstrated two significant radiological factors: cortical penetration (as defined by the disappearance of the arachnoid layer on magnetic resonance imaging scans) (relative risk, 2.067; P = 0.0148) and vascular supply from the pial-cortical arteries (as observed on angiograms) (relative risk, 2.087; P = 0.0082). CONCLUSION: Tumor infiltration into adjacent brain parenchyma and a pial-cortical blood supply are critical factors for the development of PTBE among patients with meningiomas.     

Surgery on anterior foramen magnum meningiomas using a conventional posterior suboccipital approach: a report on an experience with 17 cases.

OBJECTIVE: The advantages of a posterior "conventional" suboccipital approach with a midline incision over lateral, anterolateral, and anterior approaches to anteriorly placed foramen magnum meningiomas are discussed. METHODS: From 1991 to March 2000, 17 patients with foramen magnum meningiomas arising from the anterior or anterolateral rim of the foramen magnum underwent operations in the Department of Neurosurgery at King Edward Memorial Hospital and Seth G.S. Medical College. All patients were operated on in a semi-sitting position by use of a conventional suboccipital approach with a midline incision and extension of the craniectomy laterally toward the side of the tumor up to the occipital condyle. RESULTS: The patients ranged in age from 17 to 72 years, and the tumors ranged in size from 2.1 to 3.8 cm. The intradural vertebral artery was at least partially encased on one side in eight patients and on both sides in two patients. The brainstem was displaced predominantly posteriorly in each patient. A partial condylar resection was performed in two cases to enhance the exposure. Total tumor resection was achieved in 14 patients, and a subtotal resection of the tumor was performed in the other 3 patients. In one patient, a small part of the tumor was missed inadvertently, and in the other two patients, part of the tumor in relation to the vertebral artery and posterior inferior cerebellar artery was deliberately left behind. After surgery, one patient developed exaggerated lower cranial nerve weakness. There was no significant postoperative complication in the remainder of the patients, and their conditions improved after surgery. The average length of follow-up is 43 months, and there has been no recurrence of the tumor or growth of the residual tumor. CONCLUSION: From our experience, we conclude that a large majority of anterior foramen magnum meningiomas can be excised with a lateral suboccipital approach and meticulous microsurgical techniques.     

Choroid plexus papilloma and meningioma: coincidental posterior fossa tumors: case report and review of the literature

OBJECTIVE: We report an unusual case of an extraventricular choroid plexus papilloma (CPP) occupying the right ventral foramen magnum and lower right cerebellopontine angle (CPA), occurring together with a petro-tentorial meningioma. The clinical presentation, preoperative imaging, differential diagnosis, surgical treatment and histologic features of the two tumors are discussed. CASE DESCRIPTION: The patient presented with a 2-month history of headache, altered facial sensation, dysphagia, and gait unsteadiness. Neurologic examination confirmed a wide-based, unsteady gait, hoarse voice, anisocoria, and partial right vocal cord paralysis. Diagnostic imaging demonstrated right petro-tentorial and right ventral foramen magnum lesions, both hyperintense on contrasted images and suggestive of meningiomas. A right suboccipital craniotomy and far lateral approach was used to resect both tumors. The petro-tentorial tumor was a histologically confirmed meningioma, but the ventral foramen magnum tumor was an extraventricular CPP. CONCLUSIONS: This is a rare occurrence of concomitant meningioma and CPP. There is no known link between these two tumors. An exophytic 4th ventricular CPP must be considered in the differential diagnosis of a CPA or foramen magnum tumor.     

Intraoperative cardiovascular collapse in an infant with Arnold-Chiari malformation

We report a case of an infant with a diagnosis of Arnold-Chiari malformation who developed acute cardiovascular collapse during posterior fossa decompression surgery. Haemodynamic manifestations were hypotension and bigeminy characterized by resistance to conventional resuscitation. The aetiology was considered to be due to brainstem compression exerted to control surgical bleeding from an inadvertently lacerated sinus at an unusual site, the rim of the foramen magnum. Restoration of blood pressure and disappearance of arrhythmia immediately followed removal of the brainstem compression rather than volume or pharmacological resuscitation.     

Surgical margin for phosphaturic mesenchymal tumors in soft tissues: An analysis of the radiological histopathological correlation

BackgroundPhosphaturic mesenchymal tumors primarily cause tumor-induced osteomalacia, a rare paraneoplastic syndrome, and half occur in soft tissues. There are few reports about the surgical margins of these tumors. This study aimed to clarify the optimal surgical margin for phosphaturic mesenchymal tumors by analyzing radiological and histopathological features.MethodsThis study included eight cases, seven primary and one recurrent, of tumor-induced osteomalacia caused by soft-tissue phosphaturic mesenchymal tumors that were surgically treated between January 2000 and January 2019. We evaluated the radiological and histopathological features of all tumors and investigated the correlation of these features, the surgical margin, and recurrence of hypophosphatemia.ResultsThe tumors were located in superficial (n = 5) and deep (n = 3) tissues. Six of the eight tumors had a clear boundary, but five had an irregular margin. Three tumors had a hypointense rim on T2-weighted images, indicating fibrous tumor encapsulation. Histopathological analysis revealed infiltrative growth in six of the eight tumors, which correlated with an irregular margin seen on imaging. Although there was no recurrence in patients treated with an intended wide margin >1 cm, one of the three patients treated with marginal tumor resection experienced a recurrence of hypophosphatemia, with histopathological analysis showing infiltration of subcutaneous fat. In contrast, two tumors with clear boundaries, regular margins, and fibrous capsule seen on imaging, had no infiltrative growth and were cured by marginal resection. In one recurrent case, tumor infiltration was observed in the previous surgical scar, which was not detected on preoperative imaging.ConclusionsSoft-tissue phosphaturic mesenchymal tumors with an irregular boundary seen on imaging tend to be infiltrative, especially into subcutaneous fat, and should be treated by at least a 1-cm wide margin resection. Tumors with a fibrous capsule with clear and regular margins are cured by marginal margin resection. These findings could inform surgeons' decisions regarding the resection of soft-tissue phosphaturic mesenchymal tumors.     

Cystic lesion at the foramen magnum disseminated from a pituitary adenoma--case report.

A 38-year-old male presented with a cystic lesion at the foramen magnum due to intracranial dissemination from a pituitary adenoma. The primary tumor had required reoperation for regrowth twice. The tumor at the foramen magnum was removed surgically. Two smaller solid tumors were located in the left parietal convexity and the right temporal lobe. The former tumor was also removed surgically and the latter was observed. Histological examination showed the typical characteristics of pituitary adenoma in both surgical specimens. Immunohistochemical staining with MIB-1 and p53 antibodies showed low (< 1%) and negative reaction. Patients with pituitary adenoma, even benign tumors, must be carefully followed up for signs of metastasis.     

An extreme lateral approach to intradural lesions of the cervical spine and foramen magnum

Meningiomas and neurofibromas are the most common intradural extramedullary tumors of the foramen magnum and cervical spine. Many of these tumors are located ventral or ventrolateral to the spinal cord and medulla. Posterior approaches, although adequate for the management of most of these tumors, can sometimes result in incomplete removal of the tumor and exacerbation of the neurological deficits. Although the transoral and transcervical approaches provide a direct route to the tumor, the exposure of the lateral margins in the case of large tumors is inadequate. In addition, because of the removal of vertebral bodies, subsequent fusion may be necessary. In the present report, an extreme lateral approach to the foramen magnum and cervical spine for the removal of intradural tumors is described. The approach provides a lateral exposure of the tumor-cord/stem interface, thus permitting safe dissection without retraction of the cord. The entire longitudinal and lateral extent of the tumor and also its extradural extension can be can be managed by this approach. This approach can be considered in such a group of patients harboring entirely ventral or recurrent tumors for which the conventional posterior approach has failed. Six patients who underwent this procedure are described to illustrate its application.     

Transcondylar fossa approach to treat ventral foramen magnum meningioma--case report

A 41-year-old female presented with a meningioma of the craniocervical junction manifesting as tetraparesis and vesicourethral dysfunction. Neuroradiological examinations showed a homogeneous enhanced mass lesion extending from the foramen magnum to the upper aspect of the second vertebral body. The tumor was totally removed via the transcondylar fossa approach, which is one type of the lateral approach. She was discharged without neurological deficits. The transcondylar approach is often utilized for lesions that occupy the ventral portion around the foramen magnum. The transcondylar fossa approach, a variation of the transcondylar approach, is a refined technique which obtains a closely similar surgical working field. Use of the transcondylar fossa approach remains controversial when treating patients with little brain stem dislocation, a small condylar fossa, and a protruding occipital condyle, but the approach can easily be converted to the transcondylar approach. The transcondylar fossa approach could become a standard method to access the craniocervical junction.     

Foraminal syringomyelia: Suggestion for a grading system

Summary The standard treatment of foraminal syringomyelia includes foramen magnum decompression and duraplasty. Improvement or stabilization of the disease are achieved in most of cases. However, at least one third of patients are reported to receive little or no benefit.In this paper we retrospectively reviewed a series of 40 consecutive foramen magnum decompressions in order to identify the possible pre-operative outcome predictors. Based on clinical evolution, neurological impairment and radiological features, a scale of severity was fixed and retrospectively tested. A pre-operative score was obtained for each patient and was correlated with the surgical results. Then a four level grading system was derived. All grade I and grade II patients achieved good results (improvement or stabilization), whereas grade III patients showed intermediate behaviour and grade IV invariably worsened. On this basis, surgical results of foramen magnum decompression might be further improved provided that a careful pre-operative selection is made.     

Sporadic desmoid tumors of the chest: long-term follow-up of 28 multimodally treated patients

Introduction: Desmoids of the chest are extremely rare borderline tumors. Radical surgical resection is considered to be the primary treatment. Achieving negative margins is often a challenge. Cases with positive surgical margins are associated with high risk of local recurrence. Methods: A retrospective multicenter review was undertaken of 28 patients who underwent surgery for sporadically appearing desmoids of the chest between 1988 and 2008. Clinico-pathological data were investigated in detail. Authors have statistically analyzed the relationships between gender, age, tumor size, radicality of the first surgery, impact of the pharmacologic treatment, estrogen receptor positivity, and the development of local recurrences after a median follow-up period of 104 months. Results: Primary surgery was radical in 14 patients (50%). Mean pathologic diameter was 72.14 mm. Wide surgical excision was performed in 27 primary cases, out of which 10 cases (37%) were full- and 17 cases (63%) partial-thickness chest wall resections. Synthetic mesh stabilization was used in nine cases and soft tissue coverage in six patients. Morbidity rate was 25%. Recurrences were found in 63% of the cases, with a mean time of 30.5 months to first recurrences. Our investigation confirmed that microscopically free surgical margin of the first tumor resection significantly affected local tumor control. Conclusions: Because the radicality of the first surgical resection is of essential importance for long-time local control of chest desmoids, accurate preoperative diagnostics and well-planned aggressive surgical resection of the primary tumor is recommended. Due to the low incidence of desmoids, multicentric randomized investigations would be mandatory to establish evidence-based protocol for desmoid tumors.     

Surgical treatment of skull base chondrosarcomas

Skull base chondrosarcomas are rare tumors and individual experience with their management is limited. We present a series of such tumors treated at our institution. Particular attention was paid to their extension pattern, choice of surgical approach, and outcome. Twenty-five patients were operated consecutively over a period of 19 years. Their clinical presentation, radiological features, surgical treatment, early and late treatment outcome, as well as survival rate were analyzed. The most frequent initial symptom was abducent palsy. The typical bone destruction of the petrous apex was found in 83%. Chondrosarcomas extended in 92% to the posterior cranial fossa. Total number of surgeries was 39. The operative approach was tailored to each case. The retrosigmoid approach was used in 30.8%, the pterional in 23%, and the transethmoid in 15.4%. Total tumor removal was achieved in 19 of the surgeries. New neurological deficits immediately after surgery appeared in 33.3%. The perioperative mortality was 0%. The average Karnofsky performance score at last follow-up was 91%, and 5- and 10-year survival rates were 95%. Individually tailored approach in skull base chondrosarcomas allows radical removal with low morbidity rates and without mortality. Given the good long-term prognosis, surgical treatment should not deteriorate significantly patients' quality of life.