Imaging of cerebellopontine angle lesions: an update. Part 1: enhancing extra-axial lesions (original) (raw)
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Tumors of the cerebellopontine angle (CPA) are frequent; acoustic neuromas and meningiomas represent the great majority of such tumors. However, a large variety of unusual lesions can also be encountered in the CPA. The site of origin is the main factor in making a pre-operative diagnosis for an unusual lesion of the CPA. In addition, it is essential to analyze attenuation at computed tomography (CT), signal intensity at magnetic resonance (MR) imaging, enhancement, shape and margins, extent, mass effect, and adjacent bone reaction. CPA masses can primarily arise from the cerebellopontine cistern and other CPA structures (arachnoid cyst, nonacoustic schwannoma, aneurysm, melanoma, miscellaneous meningeal lesions) or from embryologic remnants (epidermoid cyst, dermoid cyst, lipoma). Tumors can also invade the CPA by extension from the petrous bone or skull base (cholesterol granuloma, paraganglioma, chondromatous tumors, chordoma, en-dolymphatic sac tumor, pituitary adenoma, apex petrositis). Finally, CPA lesions can be secondary to an exophytic brainstem or ventricular tumor (glioma, choroid plexus papilloma, lymphoma, hemangioblas-toma, ependymoma, medulloblastoma, dysembryoplastic neuroepithe-lial tumor). A close association between CT and MR imaging findings is very helpful in establishing the preoperative diagnosis for unusual lesions of the CPA. Abbreviations: CPA cerebellopontine angle, CSF cerebrospinal fluid
Evaluation of Extra Axial Cerebellopontine Angle Tumours through MRI
Journal of Dhaka Medical College, 2020
Aim: This study aimed to evaluate the incidence of extra-axial cerebellopontine angle tumours and to characterize extra-axial cerebellopontine angle tumours. Methods: The study was carried out in Dhaka Medical College for the duration of 2 years from July 2016 to July 2018. All patients with clinical suspicion of CP angle tumours subjected 1.5 T MR imaging system. Total 30 patients were evaluated during this period. Results: Extra-axial CPA tumours accounts for 7-10% of brain tumours. Most common extraaxial CPA tumour is schwannoma (60%), followed by meningioma (27%), epidermoid (7%), arachnoid cysts (7%). 51-60 years is the most common age group involved. Schwannomas are common extra-axial CPA tumours which are enhancing round masses most commonly arise from the vestibular nerve and associated with enlargement of the internal auditory canal. Meningiomas are the second most common extra-axial CP angle tumours which oval or hemispheric lesions with a broad attachment to tentorium or ...
Academic Radiology, 1998
Magnetic resonance imaging (MRI) has long been regarded as a major advance in identifying and characterizing cerebellopontine angle (CPA) lesions (1-5). Its technical performance is not in doubt, and formal analyses (7-12) have shown that it compares favorably with computed tomography (CT) (augmented by either or both intravenous contrast medium or cisternal air meatography) (13). The use of MRI for evaluation of CPA lesions gained qualified support in Kent and Larson's (14) seminal paper on the clinical efficacy of MRI of the brain and spine. However, little has been published on the therapeutic impact (15) (the effect on patient health) following the introduction of MRI into the diagnostic process for patients with possible CPA lesions. Nevertheless, by 1989, screening for such lesions had become a significant source (21%) of cranial MRI referrals (16). Since then, diagnostic performance has been improved (17) with the use of thinner slices, faster data acquisition, and gadolinium DTPA enhancement. The discovery of an acoustic neurinoma usually prompts surgery , although a conservative approach may be appropriate for a small lesion in an elderly patient (20). Recent research (21,22) has highlighted the use of MRI as an initial investigation for patients presenting with asymmetric audio-vestibular symptoms. If imaging protocols are limited (23,24) and other less definitive tests are avoided, this is not an expensive approach. What is not known, however, is what diagnostic and therapeutic Acad Radiol 1998; 5(suppl 2):$306-$309 $306
Incidental findings on magnetic resonance imaging screening for cerebellopontine angle tumours
The Journal of Laryngology & Otology, 2000
The otolaryngologist who requests magnetic resonance imaging (MRI) scans to exclude cerebellopontine angle (CPA) tumours may discover incidental pathologies. We retrospectively reviewed the results of 644 consecutive MRI screening scans with the aim of identifying findings other than CPA tumours. Two hundred and eighty-nine (45 per cent) scans featured one or more anomalies or abnormalities, including CPA tumour (23, four per cent), vascular loop (30, five per cent), basilar artery ectasia (13, two per cent), multiple high signal areas (135, 21 per cent), brain atrophy (52, eight per cent), sinus findings (56, nine per cent), middle ear/mastoid disease (34, five per cent), and a variety of other findings (39, six per cent) including clinically serious lesions (11, two per cent). The significance and management of these incidental findings is discussed. The majority were not clinically significant but the occasional presence of a serious incidental pathology should be borne in mind. ...
Meningeal Carcinomatosis of the Cerebellopontine Angle and Internal Auditory Canal
The Neuroradiology Journal, 1999
Most CPA and lAC region neoplasms are benign. Malignant tumour represent about 2% of the lesions and metastatic lesions account for 0.2 to 2% of all neoplasms of this region. In a group of 82 patients with meningeal carcinomatosis, 11 patients (16%) with PCA and lAC metastatic lesions were identified. In three cases the original tumour was a breast carcinoma, while in the other eight cases it was a sarcoma, PNET, glioma, leukaemia, lymphoma, medulloblastoma and one tumour of unknown origin. In five cases both PCA and lAC presented abnormal contrast enhancement of nodular type; in four patients only lAC and in two only PCA were involved. IACs were involved bilaterally or monolaterally in four cases each, while PCAs presented bilateral involvement in five cases and monolateral in one. In two cases bilateral Vth cranial nerves and cavernous sinuses were present and all the patients had dural or leptomeningeal carcinomatosis outside the PCAs and IACs. Unlike literature reports in which only 25% of IACs carcinomatosis have a negative clinical picture, we found clinically tested hearing pathology, in only 1111 patients, and involvement of other cranial nerves in only 2/11 patients. From the MR point of view, CPA and lAC carcinomatosis is characterized by bilateral or, less frequently monolateral nodular or linear contrast enhancement inside the lAC and along the dural lining of the CPA and it usually not visible in non contrast SE T1 and T2 sequences. Carcinomatosis is always associated with more diffuse dural or leptomeningeal secondary neoplastic involvement, but the association with other cranial nerve carcinomatosis is not the rule. The more frequent involvement of these regions may depend on the length of the VIIth and VIIIth cranial nerves (and this observation may also explain the more frequent association with Vth cranial nerve carcinomatosis) and on the volume of the CPA cistern, that allows a more diffuse and longer contact between the nerves and the meninges and the metastatic lesions floating in the cerebrospinal fluid .
Metastatic lesions involving the cerebellopontine angle
AJNR. American journal of neuroradiology
To evaluate the clinical and MR findings of metastatic lesions involving the cerebellopontine angle (CPA), which may be useful in differentiating them from the more commonly occurring benign CPA lesions. Clinical and MR findings of 14 patients with clinical/radiologic (seven) or pathologic (seven) diagnoses of CPA metastasis were retrospectively reviewed. Useful clinical findings included acute onset and rapid progression of cranial nerve symptoms, especially 7th and/or 8th cranial nerve deficits (92.9%). Cranial nerve symptoms could be unilateral (50%) and frequently involved multiple cranial nerves (64.3%). MR findings showed significantly more extensive disease than suggested by clinical presentation, with 100% of patients having multiple cranial nerve involvement and 85.7% bilateral. Useful MR findings included small and/or bilateral CPA-enhancing lesions with relative isointensity to brain parenchyma on precontrast MR, with associated findings of multiple and/or bilateral crani...
Rare lesions of the cerebellopontine angle
Turkish Neurosurgery, 2010
Vestibular schwannomas, meningiomas and epidermoids account for a vast majority of the lesions occurring in the cerebellopontine angle (CPA). Neoplastic and non-neoplastic pathologies other than these tumors constitute 1% of all lesions located in the CPA. The aim of this study was to reveal our experience in the treatment of the rare lesions of the CPA. We have retrospectively reviewed the medical files and radiological data of all patients who underwent surgery involving any kind of pathology in the CPA. We have excluded those patients with a histopathological diagnosis of meningioma, schwannoma and epidermoids. Our research revealed a case of craniopharyngioma, a case of chloroma, a case of solitary fibrous tumor, a case of pinealoblastoma, a case of atypical teratoid rhabdoid tumor, a case of an aneurysm, a case of hemorrhage and a case of abscess.
A retrospective study of cerebellopontine angle tumours: A single instituitional study
IP Indian Journal of Anatomy and Surgery of Head, Neck and Brain
Introduction: Cerebellopontine angle (CPA) tumors are rare intracranial neoplasms that arise in the region between the cerebellum and the pons. 1 These tumors can be challenging to treat due to their complex anatomy and proximity to critical neurovascular structures. Surgical intervention is often necessary to achieve a favorable outcome. Aims and Objectives: The primary objectives of this retrospective study are to analyze the clinical and radiological characteristics of cerebellopontine angle tumors, identify pathological types, assess surgical resectability, and evaluate postoperative outcomes. Materials and Methods: The study enrolled 14 patients who underwent surgical intervention for cerebellopontine angle tumors at Armed forces medical college, Pune. A retrospective analysis was performed, considering demographic data, clinical presentations, imaging characteristics and surgical outcomes. Results: Vestibular schwannoma was the predominant tumor type with majority of tumors manifesting between third to fifth decades. Clinical manifestation included SNHL, cerebellar dysfunction, headache and sensory trigeminal dysfunction. A substantial proportion (86%) presented with no useful hearing preoperatively. Surgical outcomes indicated varying degrees of success, with total resection achieved in a subset of cases. Notably, anatomical preservation of the facial nerve was accomplished in a significant proportion of patients. Postoperative assessments, using the House Brackmann system, revealed positive facial nerve function outcomes in a substantial percentage. Complications included cerebrospinal fluid leak (14%), meningitis(7%) and lower cranial nerve paresis (7%). Conclusion: In conclusion, surgical intervention plays a crucial role in the management of cerebellopontine tumors. The choice of surgical approach should be individualized based on tumor characteristics and patient factors, with the goal of achieving maximum tumor resection while minimizing complications. Further research and advancements in surgical techniques are needed to optimize outcomes for patients with cerebellopontine tumors. This is an Open Access (OA) journal, and articles are distributed under the terms of the Creative Commons Attribution-NonCommercial-ShareAlike 4.0 License, which allows others to remix, tweak, and build upon the work non-commercially, as long as appropriate credit is given and the new creations are licensed under the identical terms.