Mucosal Neuromas and Plexiform Neurofibromas: An Immunocytochemical Study

Mucosal neuromas (MN), a component of multiple endocrine neoplasia (MEN) type IIb, may be confused histologically with plexiform neurofibromas (PN), a component of neurofibromatosis. The ability to distinguish between these two markers for different genetic diseases is crucial, as the risk of development of medullary thyroid carcinoma and pheochromocytoma in affected patients with MEN IIb is great. We studied two cases each of MN and PN by immunocytochemistry (IC). Epithelial membrane antigen (EMA) proved to be the most useful marker. MN consisted of bundles of disorganized and tortuous nerve fibers surrounded by a thickened perineurium that expressed the cellular phenotype EMA(+), S-100(-). PN consisted of enlarged neroe fascicles with a loose myxoid stroma and was EMA negative. Thus, IC highlighted the differing pattern of growth and histogenesis of the proliferating cells in the two lesions and is likely to be especially useful in those lesions with atypical histology.     

听神经瘤术后面神经损伤的临床分类、分级研究

目的研究听神经瘤术后面神经颅内段损伤的分类、程度及临床分级。方法分析病理诊断明确的165例听神经瘤病例,肿瘤大小1.5~5.5 cm,术前面神经功能障碍19例。术中面神经损伤程度按Sunderland五级分类法分为Ⅰ级85例,Ⅱ级37例,Ⅲ级21例,Ⅳ级9例,Ⅴ级13例。结果随访1~3年,面神经功能House-BrackmannⅠ级88例,Ⅱ级12例,Ⅲ级20例,Ⅳ级9例,Ⅴ级3例,Ⅵ级33例。结论临床分级研究有助于量化面神经损伤的程度,提高对面神经损伤程度的认识,判断预后,评价手术效果。     

乙状窦后入路显微手术切除大型听神经瘤

目的探讨乙状窦后入路显微镜下切除大型听神经瘤的手术方法及临床意义。方法采用乙状窦后入路显微手术切除，对手术入路、显微手术技巧、手术后处理及并发症防治进行系统分析。结果临床应用15例，其中肿瘤全切除12例，次全切除3例，面神经解剖学保留13例，耳蜗神经解剖学保留6例。术后短期并发症3例，无死亡病例。结论乙状窦后入路显微镜下切除大型听神经瘤是安全的手术方法，对脑组织结构的创伤小，利于提高肿瘤全切除率并有效保护面神经和听神经的功能。     

Neurofibromatosis type 2 and auditory brainstem implantation

Neurofibromatosis type 2 （NF-2） is one of the most common single gene disorders in the nervous system.For approximately 96% of patients with NF-2 present with bilateral Schwannomas involving the eighth cranial nerves, which may be accompanied by Schwannomas involving other cranial, spinal or peripheral nerves, NF-2 is also referred to as ＂bilateral acoustic neuromas＂. Due to progression of tumors, surgery or radiotherapy, patients with bilateral acoustic neuromas will eventually suffer profound or total hearing loss, resulting in decrease of quality of life （QOL）.     

Long-term use of cellular phones and brain tumours: increased risk associated with use for > or =10 years

Aim

To evaluate brain tumour risk among long‐term users of cellular telephones.

Methods

Two cohort studies and 16 case–control studies on this topic were identified. Data were scrutinised for use of mobile phone for ⩾10 years and ipsilateral exposure if presented.

Results

The cohort study was of limited value due to methodological shortcomings in the study. Of the 16 case–control studies, 11 gave results for ⩾10 years'' use or latency period. Most of these results were based on low numbers. An association with acoustic neuroma was found in four studies in the group with at least 10 years'' use of a mobile phone. No risk was found in one study, but the tumour size was significantly larger among users. Six studies gave results for malignant brain tumours in that latency group. All gave increased odd ratios (OR), especially for ipsilateral exposure. In a meta‐analysis, ipsilateral cell phone use for acoustic neuroma was OR = 2.4 (95% CI 1.1 to 5.3) and OR = 2.0, (1.2 to 3.4) for glioma using a tumour latency period of ⩾10 years.

Conclusions

Results from present studies on use of mobile phones for ⩾10 years give a consistent pattern of increased risk for acoustic neuroma and glioma. The risk is highest for ipsilateral exposure.     

The natural history of vestibular schwannoma growth—prospective 40-year data from an unselected national cohort

BackgroundOptimal management of vestibular schwannoma (VS) is still debated and thus international consensus has not been achieved. Treatment options are observation, radiotherapy, and surgery. Knowledge on the natural history of tumor growth is essential for choice of treatment modality. The aim is to present intra-/extrameatal tumor growth and management data from a prospective, unselected national cohort of patients diagnosed with VS during the period 1976–2015.MethodsSince 1976, all data from patients diagnosed with sporadic VS in Denmark have been referred to our national treatment center, where they have been entered prospectively into the national database. Data on tumor localization, growth, and treatment were retrieved. Growth definition: >2 mm by linear measurement, in accordance with the Tokyo 2001 consensus-meeting recommendations.Results3637 cases of VS were diagnosed, in which 1304 patients had surgery and 21 received radiotherapy post diagnosis. 2312 patients were observed with mean follow-up of 7.33 years. Of these, 434(19%; 102 intra-and 332 extrameatal tumors) changed to active treatment during the observation period due to tumor growth. 5 years after diagnosis, 21% of the intrameatal tumors exhibited growth during observation, whereas 37% of extrameatal tumors had grown, increasing to 25% intrameatal and 42% extrameatal after 10 years. Following growth, the intrameatal tumors were mostly observed further and the extrameatal mostly underwent surgery. Tumor growth occurred mainly within the first 5 years post diagnosis.ConclusionThis natural history study documents the growth occurrence of both intra-and extrameatal VS during the first 12 years after diagnosis and should be used in patient counseling, management, and treatment decision making.     

The role of fasciae in Civinini–Morton's syndrome

This study evaluates the pathogenetic role of the perineural connective tissue and foot fasciae in Civinini–Morton's neuroma. Eleven feet (seven male, four female; mean age: 70.9 years) were dissected to analyse the anatomy of inter‐metatarsal space, particularly the dorsal and plantar fasciae and metatarsal transverse ligament (DMTL). The macrosections were prepared for microscopic analysis. Ten Civinini–Morton neuromas obtained from surgery were also analysed. Magnetic resonance images (MRIs) from 40 patients and 29 controls were compared. Dissections showed that the width of the inter‐metatarsal space is established by two fibrous structures: the dorsal foot fascia and the DMTL, which, together, connect the metatarsal bones and resist their splaying. Interosseous muscles spread out into the dorsal fascia of the foot, defining its basal tension. The common digital plantar nerve (CDPN) is encased in concentric layers of fibrous and loose connective tissue, continuous with the vascular sheath and deep foot fascia. Outside this sheath, fibroelastic septa, from DMTL to plantar fascia, and little fat lobules are present, further protecting the nerve against compressive stress. The MRI study revealed high inter‐individual variability in the forefoot structures, although only the thickness of the dorsal fascia represented a statistically significant difference between cases and controls. It was hypothesized that alterations in foot support and altered biomechanics act on the interosseous muscles, increasing the stiffness of the dorsal fascia, particularly at the points where these muscles are inserted. Chronic rigidity of this fascia increases the stiffness of the inter‐metatarsal space, leading to entrapment of the CDPN.     

Dural Defect Repair in Translabyrinthine Acoustic Neuroma Surgery and Its Implications in Cerebrospinal Fluid Leak Occurrence

Cerebrospinal fluid (CSF) leak is a complication that may occur after translabyrinthine (translab) acoustic neuroma (AN) removal. The aim of this study is to verify the incidence of CSF leak using two techniques for dural defect closure in translab AN surgery and present a new technique for dural repair. A retrospective study was held, reviewing charts of 34 patients in a tertiary neurotologic referral center. Out of these 34 patients that underwent translab AN excision in a 1-year period, 18 had their dural defect repaired using only abdominal fat graft and 16 using synthetic dura substitute (SDS) plus abdominal fat tissue. One patient (5.5%) in the first group had CSF leak and 1 (6.2%) in the second group had CSF leak postoperatively. Our data suggest that there are no significant differences in CSF leak rates using both techniques, although studies in a larger series must be undertaken to conclude it. We believe that the development of some points in the new technique for dural repair can achieve better results and reduce the CSF leak incidence in the translabyrinthine acoustic neuroma surgery in the near future.