Incidental Findings of a Vestibular Schwannoma on 18F-Choline PET/CT.

ABSTRACT: We report an increased uptake of 18F-choline in the right cerebellopontine angle area in a 73-year-old man with biochemical failure prostate cancer after radical prostatectomy, potentially suggestive of bone metastasis in the base of the skull. A brain MRI was also performed showing an intense gadolinium enhancement focus in the same area, concordant with a right vestibular schwannoma, subsequently histologically proven. This case underlines that schwannoma is a diagnostic pitfall in 18F-choline PET/CT, suggesting this radiolabeled tracer as a promising tool for brain tumors characterization due to its higher signal-to-background ratio than 18F-FDG.

Tumor-to-Tumor Metastasis of Hepatocellular Carcinoma to Vestibular Schwannoma.

BACKGROUND: Intracranial metastasis is a common complication of systemic malignancy. A rare subset of intracranial masses constitutes tumor-to-tumor metastasis, in which an extracranial neoplasm hematogenously spreads to an existing intracranial lesion. CASE DESCRIPTION: Here we present the unique case of a 59-year-old man with known hepatocellular carcinoma who presented with acute headaches, double vision, vertigo, and gait instability in the context of 2 years of right-sided hearing loss. Head imaging showed a heterogeneous right cerebellopontine angle mass extending into the porus acousticus with adjacent cerebellar edema. Histopathologic analysis after resection found coexisting hepatocellular carcinoma within a vestibular schwannoma. CONCLUSIONS: Tumor-to-tumor metastasis is an important consideration in the diagnostic work-up and treatment of patients with known systemic malignancy who present with a new intracranial lesion. This pathologic entity could be missed if this patient were treated with single-fraction radiosurgery such as Gamma Knife.

Internal Auditory Canal Tumor as an Incidental Finding on a Choline PET/CT Scan in a Prostate Cancer Patient.

An 84-year-old man with a history of prostate cancer, treated with radiotherapy, presented with an increase in PSA levels. F-choline PET/CT showed foci of increased choline uptake in L4 and L5 vertebrae, suggestive of bone metastases and another focus in the right cerebellopontine angle. A brain MRI revealed a focus of intense contrast enhancement in the same region, consistent with an acoustic neuroma.

Identifying predictors of early growth response and adverse radiation effects of vestibular schwannomas to radiosurgery.

PURPOSE: To determine whether pre-treatment growth rate of vestibular schwannomas (VS) predict response to radiosurgery. METHODS: A retrospective review of a prospectively maintained database of all VS patients treated with 12Gy prescription dose between September 2005 and June 2011 at our institution using the Leksell Model 4C Gamma Knife Unit was conducted. Patients who had a minimum of 12-months clinical and radiological assessment before and after radiosurgery were included in this study. Tumor growth rates were calculated using specific growth rate (SGR). Tumor volumes were measured on FIESTA-MRI scans using ITK-SNAP v2.2. RESULTS: Following radiosurgery, twenty-seven (42.9%) patients showed a significant decrease in volume after one year, twenty-nine (46.0%) stabilized, and seven (11.1%) continued to grow. There was no correlation between VS pre-treatment SGRs with post-treatment SGRs (p = 0.34), and incidence of adverse radiation effects (ARE). The reduction in tumors' SGRs after radiosurgery was proportional to pre-treatment SGRs, although this correlation was not statistically significant (p = 0.19). Analysis of risk factors revealed a positive correlation between post-treatment SGRs and incidence of non-auditory complications, most of which were attributed to ARE (p = 0.047). CONCLUSION: Pre-treatment growth rate of VS does not predict tumor response to radiosurgery or incidence of ARE. VS with higher SGRs post-radiosurgery are more likely to experience ARE.

Cardiac and acoustic metastases in relapsing melanoma.

Herein we report the case of a 45-year-old woman with known history of malignant melanoma, complaining recent onset of bilateral hearing problems initially addressed to acoustic neuroma. Dedicated (18)F-FDG PET/CT and MR imaging documented the presence of 3 areas of pathologic uptake in the V-VII-VIII cranial nerves, other 2 in the neck and in the medullary sheath, and another unexpected lesion in the interventricular septum. All lesions showed intense (18)F-FDG uptake, high precontrast T1-weighted signal, contrast enhancement in T1-weighted sequences with gadolinium, and hypervascularization/high signal in T2-weighted images: these features were considered in keeping with diffused malignant melanoma metastatization.

The effect of early customized vestibular rehabilitation on balance after acoustic neuroma resection.

OBJECTIVE: To compare the effect of early customized vestibular rehabilitation with general instructions in patients after acoustic neuroma surgery. SETTING: Tertiary referral centre. SUBJECTS: Fifty-three patients after surgery. DESIGN: A prospective assessor-blinded, randomized controlled trial. INTERVENTIONS: After stratification for age (<50 years; >or=50 years), patients were randomly allocated into groups receiving general instructions or customized vestibular rehabilitation protocols for 12 weeks. OUTCOME MEASURES: Standing Balance Sum, Timed Up and Go test, Tandem Gait and Dynamic Gait Index. Balance performance was assessed preoperatively, at discharge (one week after surgery), three, six, nine, 12, 26 and 52 weeks after surgery. RESULTS AND DISCUSSION: All subjects clearly improved within the first six weeks after surgery. However, older subjects receiving vestibular rehabilitation performed significantly (P<0.05) better on standing balance, Timed Up and Go test and Tandem Gait, when compared with the older group that received only general instructions. This effect persisted up to 12 weeks and also became apparent on the Dynamic Gait Index. In addition, the older vestibular rehabilitation group had better balance scores at 12 weeks when compared with their original preoperative scores (P<0.05). This pattern remained even up to one year after surgery (P<0.05). CONCLUSION: In patients over 50, early vestibular rehabilitation facilitates recovery of postural control after acoustic neuroma surgery. Customized vestibular rehabilitation should be given in addition to general instructions that stress the need of exposure to movement. Retention of the early beneficial effects even one year after surgery stresses the importance of customized vestibular rehabilitation.

Intramedullary tumours in patients with neurofibromatosis type 2: MRI features associated with a favourable prognosis.

AIM: To assess the magnetic resonance imaging (MRI) features and natural history of intramedullary tumours in patients with neurofibromatosis type 2 (NF2). MATERIALS AND METHODS: Eleven NF2 patients with intramedullary spinal cord tumours were identified from the database of the multidisciplinary NF2 clinic. All the imaging studies of these patients were individually reviewed by two neuroradiologists to evaluate the size, number, location, imaging characteristics, and interval growth of the intramedullary tumours. RESULTS: Two of the 11 patients had lesions that required surgery. Both these lesions were in the cervical region, and extended over three and five segments respectively. Nine patients with a mean imaging follow-up period of 77 months had lesions that remained stable, apart from the development of small peritumoral cysts in three. The lesions were well circumscribed, often multiple, usually less than 1cm in diameter, and were most frequently found in the cervical cord. CONCLUSION: The majority of intramedullary tumours in NF2 patients are very slow growing and share certain MRI features that differ from those of progressive or symptomatic lesions.

A true malignant schwannoma of the eighth cranial nerve: case report.

OBJECTIVE: The clinical presentation, pathology, treatment, and outcome of a 43-year-old woman with a malignant peripheral nerve sheath tumor arising from a benign schwannoma of the eighth cranial nerve are presented. CLINICAL PRESENTATION: Initially, the tumor was debulked. After finding malignant areas within the benign tumor, it was considered to be a malignant transformation of a previously benign tumor. INTERVENTION: Aggressive total resection was obtained during a second-stage procedure. Postoperatively, the tumor bed was radiated for palliation. CONCLUSION: Despite surgery, radiation, and chemotherapy, the patient died rapidly as a result of disseminated metastatic disease.

[Differential diagnoses of acute bilateral hearing loss in a patient with metastatic bronchial carcinoma]. / Differenzialdiagnosen einer beidseitigen akuten Hörminderung bei einem Patienten mit metastasierendem Bronchialkarzinom.

The first symptom of an acoustic neuroma in about 50% of the patients is hearing loss, which occurs suddenly in about 5-10% of cases. Acute progressive hearing loss is associated with a broad spectrum of differential diagnoses. Cerebellar and hepatic metastases from a bronchial carcinoma were previously diagnosed in the case presented here, and the most probable causes of the progressive hearing loss, e.g. idiopathic sudden deafness, infection and tumor-associated factors, were considered and diagnostically analyzed. The discussion ultimately focused on the clinical and radiological signs of bilateral acoustic neuroma. The patient's history and clinical findings yielded no indication of neurofibromatosis (type 1/2). Nevertheless, the constellation of findings suggests that the bilateral hearing loss was caused by a bilateral acoustic neuroma.

Direct costs of microsurgical management of radiosurgically amenable intracranial pathology in Germany: an analysis of meningiomas, acoustic neuromas, metastases and arteriovenous malformations of less than 3 cm in diameter.

BACKGROUND: The purpose of the analysis was to appreciate and compare the effective direct costs of microsurgical treatment of intracranial pathology potentially amenable to radiosurgery as they arose in 1998-99. METHOD: Treatment costs of 127 microsurgically treated patients harbouring an arteriovenous malformation (AVM), acoustic nEuroma, meningioma or brain metastasis potentially amenable to radiosurgery were reviewed. Costs for the surgical procedure, ICU care, medical and nursing care on the ward, interclinical bills (ICB) for services provided by other departments and the overhead for basic hotel service were added. For comparison Gamma Knife costs were calculated by dividing the global operating cost of the Gamma Knife centre by the number of patients treated in 1999. FINDINGS: Average hospitalisation time for the entire microsurgical patients was 15,4+/-8,6 days. The patients spent an average of 1,2+/-2,8 days on ICU. Average operating time for all patients, including preparation, was 393+/-118 minutes. Average costs for the microsurgical therapy were Euro10.814+/-6.108. These consisted of Euro1417+/-426 for the surgical procedure, Euro1.188+/-2.658 for ICU care, Euro2.333+/-1.582 for medical and nursing care on the ward, Euro1.671+/-1.433 for interclinical bills and Euro 4.204+/-2.338 for basic hotel service (overhead, Euro273/day). 70% of the microsurgically treated patients needed ancillary inpatient rehabilitation or radiotherapy resulting in an average additional cost for all patients of Euro2.744. Furthermore 20% of the microsurgically treated patients required an unplanned readmission after discharge, resulting in an average additional costs for all patients of Euro1.684. Average overall costs per patient including ancillary therapy and unplanned readmissions amounted to Euro15.242. For comparison, Gamma Knife treatment costs per patient amounted to Euro7.920 in 1999. INTERPRETATION: The current analysis showed that for established radiosurgical indications the primary costs of microsurgery exceeded the costs of radiosurgery. Differences with regard to additional expenses as a consequence of disability were not addressed in this study. Microsurgical management as well as Gamma Knife radiosurgery have potential for economic improvement.

[Metaplastic ossification in an acoustic neurinoma]. / Metaplastische Ossifikation in einem Akustikusneurinom.

We report the case of a 52-year-old woman with a cerebellopontine angle tumor, which appeared to have arisen from the 8th nerve. Microscopically the tumor was proved to be an acoustic neurinoma and showed unusual findings such as inclusions of mature bone and bone marrow. The histogenesis and diagnostic relevance of the very rare heterotopic osteogenesis in acoustic neurinomas is discussed.

An extensive vestibular schwannoma with both intracranial spread and lateral extension to the external auditory canal.

An extensive schwannoma in a 54-year-old woman is described. There was extension intracranially to involve the brain stem, laterally to fill the middle ear and external meatus, and inferiorly into the infratemporal fossa. Initially the intracranial portion of the tumour was excised. Later a second operation was undertaken to remove the residual tumour from the temporal bone and infratemporal fossa.

Craniocervical manifestations of neurofibromatosis: MR versus CT studies.

Craniocervical manifestations of neurofibromatosis on magnetic resonance (MR) imaging are described in three patients and compared with those on CT. Using MR, intracranial gliomas, schwannomas, and neurofibromas were detected as well as with CT. In addition, a brain stem lesion that was not visualized on CT and a cervical cord lesion that was not suspected clinically were diagnosed with MR. Taking into account the noninvasive nature of MR, we believe that this technique should be the primary imaging modality for screening and follow-up studies in patients with known or suspected neurofibromatosis.

Metastases to primary intracranial meningiomas and neurilemomas.

Five cases of carcinoma metastatic to intracranial meningioma or neurilemoma are presented and compared with 20 similar cases reported in the literature. The phenomenon was most often seen on autopsy (17 of 25 cases) and was found more commonly in females (3:2), with nearly 90% of donor cancers being found in breast or lung. The existence of the donor tumor, which was always found to be widely disseminated, was known prior to autopsy in only half the cases.