Cerebellopontine Angle Mass Research Articles

Bilateral cerebellopontine angle and multiple supratentorial masses

B) Neurofibromatosis type 2. Bilateral cerebellopontine angle and multiple supratentorial massesJournal of Clinical NeuroscienceVol. 13Issue 6PreviewA 19-year-old woman presented with a 3-month history of progressive tinnitus and hearing disturbance on the right side. On examination, she was deaf in the right ear. An MRI scan revealed bilateral cerebellopontine angle (CPA) masses, larger on the left than the right, despite the right-sided hearing loss, and multiple, dural-based supratentorial masses (Fig. 1). She initially underwent complete resection of the right CPA lesion in March 2005. A month later, she represented with facial numbness and an incomplete lower motor neurone facial palsy on the left and progressive ataxia. Full-Text PDF

Cerebellar glioblastoma multiforme presenting as a cerebellopontine angle mass

Cerebellar glioblastoma multiforme (GBM) is a highly malignant brain tumour, which is exceedingly rare and such tumour presenting as cerebellopontine angle (CPA) mass is even rarer. We here discuss the case of a 15-year-old girl who had cerebellar GBM presenting as CPA mass that resembled meningioma on CT scan and was managed successfully with minimal problems.

Head and neck malignant metastasis to the cerebellopontine angle

Objectives: To present 3 patients with isolated metastatic lesions to the cerebellopontine angle (CPA). The patient’s histories and clinical courses are reviewed. Methods: Clinical chart reviews of 3 patients with head and neck malignant lesions metastatic to the CPA was conducted. Results: The first patient had a temporal squamous skin cancer involving the temporal bone requiring a lateral temporal bone resection. The second and third patients had parotid adenocarcinomas with facial nerve involvement. Facial nerves were invaded by primary tumors in all 3 cases and peripheral facial paralyses were demonstrated. The CPA masses were found at 10–48 months after the primary tumor removal. One patient had developed hydrocephalus at presentation. Translabyrinthine resection of the CPA tumors was performed in all 3 cases. One patient is alive and free from disease 14 months postoperatively. One patient expired with pneumonia with disease at 21 months. The third patient died due to surgical complications on postoperative day 5. Conclusion: Malignant metastasis presenting as an isolated CPA tumor is rare. Only 1 squamous cell carcinoma and 2 adenocarcinoma from parotid malignancies metatastasizing to the CPA have been reported in the English literature. Our experience suggests that despite the poor prognosis of CNS metastasis of head and neck cancer, surgical management can provide a reasonable potential for cure and outcome in terms of palliative care.

Vertebro-basilar Dolichoectasia with Fusiform Aneurysm : Evaluation by CT Angiography.

Vertebro-basilar dolichoectasia is a rare cause of cerebello-pontine angle mass lesions [1]. These lesions are due to atherosclerotic and degenerative changes affecting the media of the arteries leading to fusiform enlargement. Usually seen in patients more than 50 years of age, it may cause brain stem infarction, compression or cranial nerve palsies. CT angiography is a non-invasive and accurate modality of imaging these vascular lesions. We report a case of vertebro-basilar dolichoectasia with fusiform aneurysm and intraluminal thrombus, diagnosed using 3-D CT angiography.

Unusual lesions of the cerebellopontine angle: a segmental approach.

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 preoperative 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, endolymphatic sac tumor, pituitary adenoma, apex petrositis). Finally, CPA lesions can be secondary to an exophytic brainstem or ventricular tumor (glioma, choroid plexus papilloma, lymphoma, hemangioblastoma, ependymoma, medulloblastoma, dysembryoplastic neuroepithelial tumor). A close association between CT and MR imaging findings is very helpful in establishing the preoperative diagnosis for unusual lesions of the CPA.

Magnetic resonance imaging in the investigation of sensorineural hearing loss: is contrast enhancement still necessary?

High resolution T2-weighted magnetic resonance (MR) imaging has been proposed as a rapid, inexpensive means of investigating patients with sensorineural deafness, particularly to exclude vestibular schwannomas. Whether the accepted 'gold standard' of contrast-enhanced T1-weighted images can be omitted, however, remains controversial. Over a 22-month period the use of axial turbo-spin echo T2-weighted images (T2W) were prospectively compared with contrast-enhanced T1-weighted spin echo scans in the evaluation of 513 patients presenting with audiovestibular symptoms. A 2-D T2W turbo spin echo (TSE) sequence with 3 mm slices was used in 340 patients while a 3-D sequence with overlapping 1 mm slices was used in 173 patients. The T2-weighted image findings were documented and subsequently compared with contrast-enhanced images. With the 2-D sequence 24 patients (25 lesions) had internal auditory meatus (IAM)/cerebello-pontine angle (CPA) masses identified by contrast-enhanced T1-weighted images, all of which were seen on the T2-weighted TSE sequence; there was one false positive 'mass' on the T2-weighted scans and one false negative case of IAM dural enhancement on T1-weighted imaging; six were considered normal initially on the T2-weighted images although three were subtly abnormal in retrospect. With the 3-D sequence three acoustic neuromas were all identified correctly with no false positive and only one false negative result (labyrinthitis). The 2-D and 3-D images were judged technically inadequate for clinical assessment in 15 and nine per cent respectively. We conclude that mass lesions of the IAM/CPA can be reliably identified on T2W TSE imaging but labyrinthine lesions may be missed without contrast enhancement. This is of particular importance in planning the management of neurofibromatosis type 2. Non-neoplastic disorders of the inner ear are also likely to be missed.

Cerebellopontine angle Hodgkin's disease

Intracranial Hodgkin's disease is a rare site of involvement, and even more rare is its presentation as a cerebellopontine angle mass. The imaging findings are non-specific but the rapid response to therapy may provide a clue to diagnosis.

平衡機能検査で異常所見に乏しかった大きな小脳橋角部腫よう症例

Most large cerebello-pontine angle (CPA) tumors usually cause typical abnormal oculomotor findings on vestibular and oculomotor examinations, reflecting brainstem and cerebellar lesions. However, we encountered four patients with large CPA tumor without the typical abnormal neurotological findings and these cases are described in this report. Case 1 : A 63-year-old female. Chief compliment (CC) was double vision. Audiovestibular examinations showed normal findings except for slight nystagmus on ENG. MRI revealed a 4.8 × 4.7 cm lesion of the right CPA. The histopathological diagnosis was CPA meningioma.Case 2 : A 58-year-old female. CC was a tinnitus. Pure tone audiometry indicated right-sided sensorineural hearing loss (SNHL). Results of vestibular examination were normal. MRI revealed a 4.0 × 3.5 cm lesion from the clivus to the CPA that was diagnosed radiologically as a meningioma. Case 3 : A 50-year-old female. CC were tinnitus and head heaviness. Audiovestibular examinations were all unremarkable. MRI revealed a 3.0 × 2.7 cm lesion of the right CPA that was diagnosed as an epidermoid cyst. Case 4 : A 48-year-old female. CC were hearing loss and tinnitus. Audiometric studies indicated right-sided moderate-to-profound SNHL. There were no responses on ABR. Vestibular examinations were unremarkable. MRI revealed a 4.2 × 4.0 cm left-sided CPA mass that was diagnosed at surgery as an acoustic neuroma with cystic changes. Previous study showed that when the CPA tumor is larger than 3 cm, ETT and OKP demonstrate abnormal findings in 70 to 78% of patients, respectively. However, in our cases, despite pronounced compressions of the brainstem and cerebellum by large CPA tumors, vestibular examinations did not reveal any significant findings. These atypical findings might have resulted from the histological characteristics and slow growth of the CPA tomor, in addition to factors related to central vestibular compensation and indivisual differences in susceptibility to the lesions.

The Role of Magnetic Resonance Imaging in Central Hearing Deficits: Beyond the Acoustic Schwannoma

Acoustic schwannoma is assumed to be the most common cause of sensory-neural hearing loss (SNHL), and many papers have described the role of magnetic resonance imaging (MRI) in the diagnosis of cerebello-pontine angle (CPA) tumours, particularly schwannoma. We retrospectively examined 72 patients complaining of different clinical syndromes and SNHL or different kinds of acoustic impairment who underwent MRI brain study excluding the presence of acoustic schwannoma and other CPA masses. In conclusion, although acoustic schwannoma is the most common cause of acquired HD, a lesion involving the neural centers of the acoustic pathway can also determine SNHL or HD. Considering the high sensitivity of MRI in the detection of acoustic intra-axial pathway lesions, an in-depth MRI examination of the brain stem and the temporal lobe is mandatory when SNHL or HD occur in patients not affected by acoustic schwannoma.

The diagnostic value of imaging the patient with dizziness. A Bayesian approach.

Imaging studies are routinely used in the evaluation of patients with dizziness. A principal concern of the ordering physician is to rule out a cerebellopontine angle (CPA) mass. The incidence of such masses in patients presenting with dizziness is quite low, however, raising the question of the value of imaging this population. To calculate the probability, using Bayes theorem, that a given patient with dizziness has a CPA mass. Meta-analysis of epidemiological data on CPA masses and of studies reporting the incidence of otologic symptoms in patients with these masses. We also conducted a study of consecutive patients with dizziness to determine the frequency of asymmetric hearing loss in this population. These data were combined in applications of Bayes theorem to calculate disease probabilities. The probability that a patient with dizziness has a CPA mass is 0.0004, indicating that 2500 imaging studies would have to be performed to identify 1 CPA mass. If patients with subjectively normal hearing are investigated (ie, those with isolated dizziness), the probability is 0.000107, indicating that 9307 scans would have to be performed to identify 1 CPA mass. If the search is restricted to those patients with dizziness and asymmetric hearing loss (the patients usually felt to be high risk), the probability is 0.00156, indicating that 638 scans would have to be performed to identify 1 CPA mass. Even when studying patients with dizziness and asymmetric hearing loss, the probability of identifying a CPA mass is sufficiently low that we do not feel imaging is generally warranted. When faced with a patient with dizziness, we recommend a careful neurologic and otologic examination. If abnormalities are detected on examination that suggest central nervous system disease or invasive otologic disease, imaging should be pursued as appropriate. In cases of acute vertigo, if the patient is at high risk for cerebrovascular disease by virtue of age and additional risk factors, imaging should probably be pursued. For the remainder of patients, if progression of hearing loss is not documented, we do not believe imaging is warranted. Progressive hearing loss with abnormal speech reception thresholds probably warrants a magnetic resonance imaging scan of the internal auditory canals.

Case report: Giant aneurysm of the intrapetrous carotid artery presenting as a cerebellopontine angle mass

Case report: Giant aneurysm of the intrapetrous carotid artery presenting as a cerebellopontine angle mass

Imaging of atypical choroid plexus papillomas

The authors report a rare case of benign choroid plexus papilloma arising in the cerebellopontine angle (CPA) in a 34-year-old man. Atypical features are described. This is the fourth case of MR evaluation of such tumor in available literature and the second case in the United States. Differential diagnosis is discussed. Choroid plexus papilloma should be considered among calcified, vascular, enhancing masses of CPA even in adulthood. The authors also report an unusual case of choroid plexus carcinoma.

Another case of acoustic schwannoma and epidermoid cyst occurring as a single cerebellopontine angle mass: Possibly not so rare?

This is the second case of adjacent occurrence of an acoustic schwannoma and epidermoid cyst in the cerebellopontine angle. This case of a 70-year-old woman is presented with a history of her illness, neuroradiologic data, and photographs during the operation. We compare this case with the first of its kind.

MRI spectrum of medulloblastoma

Medulloblastomas have been characterized as solid, homogeneously enhancing, midline masses of the posterior fossa. To evaluate atypical MRIcharacteristics, we retrospectively reviewed 13 histologically proven medulloblastomas. MRI examinations were correlated with pathologic specimens and operative reports. Atypical features included cyst formation (77%), irregular enhancement (19%), extension through fourth ventricle foramina (15%), and presentation as a cerebellopontine angle mass (8%). We conclude that “atypical” characteristics are common. In the child or young adult, medulloblastomas must be included in the differential diagnosis of any posterior fissa mass.

The Evaluation of Ear Canal, Middle Ear, Temporal Bone, and Cerebellopontine Angle Masses in Infants, Children, and Adolescents

The Evaluation of Ear Canal, Middle Ear, Temporal Bone, and Cerebellopontine Angle Masses in Infants, Children, and Adolescents

Acoustic schwannoma and epidermoid cyst occurring as a single cerebellopontine angle mass

The case of a 66-year-old man with a 3-year progressive hearing loss and a homogeneous left cerebellopontine angle mass on magnetic resonance imaging scan is described. At surgery, the major portion of the mass was a typical encapsulated, solid, acoustic schwannoma, but the most rostral portion was a distinct, flaky, cystic mass without a well-defined capsule, typical of an epidermoid cyst. The radiographic and operative findings of this unique coexistence of two different benign cerebellopontine angle masses are presented.

Acoustic Schwannoma and Epidermoid Cyst Occurring as a Single Cerebellopontine Angle Mass

Abstract The case of a 66-year-old man with a 3-year progressive hearing loss and a homogeneous left cerebellopontine angle mass on magnetic resonance imaging scan is described. At surgery, the major portion of the mass was a typical encapsulated, solid, acoustic schwannoma, but the most rostral portion was a distinct, flaky, cystic mass without a welldefined capsule, typical of an epidermoid cyst. The radiographic and operative findings of this unique coexistence of two different benign cerebellopontine angle masses are presented.

Book reviews

This monograph is based on experience of 275 cases of cerebello-pontine (CP) angle mass lesion collected by its Swiss and American authorship. The majority (60%) of these are, of course, acoustic neurinomas, but a wide spectrum of pathology accounts for the remainder, and these are described and illustrated.

Hemifacial spasm associated with epidermoid tumors of the cerebellopontine angle.

Hemifacial spasm (HFS) is rarely due to serious compressive lesions, such as tumors, aneurysms, or vascular malformations, located in the cerebellopontine angle. Because of the interesting association of HFS with epidermoid tumors, we reviewed the records of all patients with HFS and all patients with intracranial epidermoid tumors seen from January 1975 to December 1986. Of the 18 patients who had epidermoid tumors of the cerebellopontine angle, 3 (17%) had a facial movement disorder that resembled HFS at sometime during their illness. There were 429 patients who had HFS with no obvious serious compressive lesion of the facial nerve. Therefore, HFS was associated with epidermoid tumor in 0.7% of cases. All 3 patients developed other findings due to involvement of adjacent neural structures. Patients with HFS have a low probability of having a serious compressive lesion, but those with atypical features should be evaluated for cerebellopontine angle masses such as epidermoid tumors.

Primary pontine hematoma presenting as a cerebellopontine angle mass

Primary pontine hematoma presenting as a cerebellopontine angle mass