Fibrolipomatous hamartomas of the median nerve in infancy and early childhood-imaging hallmarks, symptomatology, and treatment.

A fibrolipomatous hamartoma (FLH) is a rare lesion leading to an enlargement of the affected nerve and commonly manifests at the median nerve. Symptomatic patients are mostly adolescents or adults. In children below 10 years, this entity is rather unknown and likely to be misdiagnosed. We report three children with FLH, two severely and one mildly symptomatic, all below 4 years of age at the time of first presentation. Two of three children were initially misdiagnosed. We provide a review of the pertinent clinical and radiological findings of the entity. Two patients had a characteristic macrodactyly. The two symptomatic children underwent surgical carpal tunnel decompression. The intervention relived their symptoms with a long-lasting effect. Surgical reduction of the hamartoma mass is not indicated and medical treatment non-existent. CONCLUSION: A symptomatic FLH of the median nerve is rare in children below the age of 5 years but has to be kept in mind as differential diagnosis in case of wrist and/or palm swelling, macrodactyly, and pain in hand or forearm. MRI is diagnostic, with very characteristic features, which can also be identified in high-resolution nerve ultrasound. This article aims to increase the knowledge about the entity including the diagnostic features and the management options. What is Known: • Fibrolipomatous hamartomas (FLHs) of the median nerve are rare, possibly associated with macrodactyly and tissue growth at the wrist and thenar side of the palm. • An associated carpal tunnel syndrome typically occurs, if at all, in adulthood. What is New: • We describe two children below 4 years with symptomatic carpal tunnel syndrome, experiencing a long-lasting favorable outcome after carpal tunnel decompression. In this age group, only one other child undergoing surgery has been published so far. • MRI and high-resolution ultrasound demonstrate the characteristic features of FLHs and are the diagnostic modalities of choice. Biopsy is not recommended.

Beneficial impact of high-field intraoperative magnetic resonance imaging on the efficacy of pediatric low-grade glioma surgery.

OBJECTIVE: Intraoperative MRI (iMRI) is assumed to safely improve the extent of resection (EOR) in patients with gliomas. This study focuses on advantages of this imaging technology in elective low-grade glioma (LGG) surgery in pediatric patients. METHODS: The surgical results of conventional and 1.5-T iMRI-guided elective LGG surgery in pediatric patients were retrospectively compared. Tumor volumes, general clinical data, EOR according to reference radiology assessment, and progression-free survival (PFS) were analyzed. RESULTS: Sixty-five patients were included in the study, of whom 34 had undergone conventional surgery before the iMRI unit opened (pre-iMRI period) and 31 had undergone surgery with iMRI guidance (iMRI period). Perioperative data were comparable between the 2 cohorts, apart from larger preoperative tumor volumes in the pre-iMRI period, a difference without statistical significance, and (as expected) significantly longer surgeries in the iMRI group. According to 3-month postoperative MRI studies, an intended complete resection (CR) was achieved in 41% (12 of 29) of the patients in the pre-iMRI period and in 71% (17 of 24) of those in the iMRI period (p = 0.05). Of those cases in which the surgeon was postoperatively convinced that he had successfully achieved CR, this proved to be true in only 50% of cases in the pre-iMRI period but in 81% of cases in the iMRI period (p = 0.055). Residual tumor volumes on 3-month postoperative MRI were significantly smaller in the iMRI cohort (p < 0.03). By continuing the resection of residual tumor after the intraoperative scan (when the surgeon assumed that he had achieved CR), the rate of CR was increased from 30% at the time of the scan to 85% at the 3-month postoperative MRI. The mean follow-up for the entire study cohort was 36.9 months (3-79 months). Progression-free survival after surgery was noticeably better for the entire iMRI cohort and in iMRI patients with postoperatively assumed CR, but did not quite reach statistical significance. Moreover, PFS was highly significantly better in patients with CRs than in those with incomplete resections (p < 0.001). CONCLUSIONS: Significantly better surgical results (CR) and PFS were achieved after using iMRI in patients in whom total resections were intended. Therefore, the use of high-field iMRI is strongly recommended for electively planned LGG resections in pediatric patients.

Step-by-step education of the retrosigmoid approach leads to low approach-related morbidity through young residents.

BACKGROUND: Neurosurgery requires a profound knowledge of anatomy and surgical skills. The skull base approach is the crucial step for successful intradural performance. Resident training at experienced institutions must consider this background when educating young neurosurgeons. METHODS: From 2006-2008, 223 retrosigmoid approaches for various cerebellopontine angle pathologies have been performed at the Department of Neurosurgery Eberhard-Karls-University, Tübingen. After a minimum time of 6 months assisting, followed by participation of dissection courses and continuous anatomical training, later performing their first approaches under direct supervision of an experienced surgeon, residents perform their first retrosigmoid approaches autonomously in the operating theatre. With this study, we evaluate the surgical morbidity and the time factor related to the educational level of the surgeon. RESULTS: Comparing surgical-related morbidity between approaches performed by experienced neurosurgeons (>100 procedures) and young residents (<20 procedures), we found no significant differences concerning the incidence of cerebrospinal fluid fistulae, sinus lacerations, wound infections, cranioplasty dislocations, or occipital nerve neuromas. Even the mean time for the procedure (positioning, time-to-dural incision) was not significantly longer in the trainee group. CONCLUSION: Respecting the stepwise educational levels for skull base surgery, including microanatomical studies, educational courses, and expert guidance at surgery, the retrosigmoid approach can be performed by young residents without increased morbidity at experienced institutions.

Insular gliomas and the role of intraoperative assistive technologies: Results from a volumetry-based retrospective cohort.

INTRODUCTION: In the field of Glioma surgery, there has been an increasing interest in the use of assistive technologies to overcome the difficulty of preserving brain function while improving surgical radicality. In most reports, tumor localization has seldom been considered a variable and the role of intraoperative adjuncts is yet to be determined for gliomas of the insula. OBJECTIVES: To evaluate the efficacy of fluorescence-guided resection with 5-ALA, intraoperative neurophysiological monitoring (IOM), neuronavigation, and tractography in the Extent of Resection (EOR), functionality scores, overall survival (OS) and progression-free survival (PFS) in a retrospective cohort of insular gliomas. METHODS: We reviewed all cases of insular tumors operated on at the Department of Neurosurgery, University Hospital of Tübingen - Germany, between May 2008 and November 2013. EOR was determined by volumetric analysis. Mann Whitney, Chi-square and Kaplan Meier functions were used for assessment of each technology's effect on primary and secondary outcomes. RESULTS: 28 cases (18 men (64%) and 10 women (36%); median age at diagnosis: 52.5 years, range 12 - 59) were considered eligible for analysis. High grade and low grade gliomas accounted for 20 (71%) and 8 (29%) cases, respectively. The most used technologies were IOM (64%) and Neuronavigation (68%). 5-ALA was the only technique associated with EOR ≥90% (p=0.05). Tractography determined improvement in the Karnofsky Performance Scale (50% vs. 5% cases improved, p=0.02). There was a positive association between the use of neuronavigation and overall survival (23 vs. 27.4 months, p=0.03), but the use of 5-ALA was associated with shorter OS (34.8 vs. 21.1 months, p=0.01) and PFS (24.4 vs. 11.8, p=0.01). CONCLUSIONS: We demonstrate for the first time that for insular gliomas 5-ALA plays a role in achieving higher EOR, although this technology was associated with poor OS and PFS; also tractography and neuronavigation can be of great importance in the treatment of insular gliomas as they determined better functionality and OS in this study, respectively. Prospective studies with a more prominent sample and proper multivariate analysis will help determine the real benefit of these adjuncts in the setting of insular gliomas.

Distinguishing recurrent high-grade gliomas from radiation injury: a pilot study using dynamic contrast-enhanced MR imaging.

RATIONALE AND OBJECTIVES: The accurate delineation of tumor recurrence and its differentiation from radiation injury in the follow-up of adjuvantly treated high-grade gliomas presents a significant problem in neuro-oncology. The aim of this study was to investigate whether hemodynamic parameters derived from dynamic contrast-enhanced (DCE) T1-weighted magnetic resonance imaging (MRI) can be used to distinguish recurrent gliomas from radiation necrosis. MATERIALS AND METHODS: Eighteen patients who were being treated for glial neoplasms underwent prospectively conventional and DCE-MRI using a 3T scanner. The pharmacokinetic modelling was based on a two-compartment model that allows for the calculation of K(trans) (transfer constant between intra- and extravascular, extracellular space), v(e) (extravascular, extracellular space), k(ep) (transfer constant from the extracellular, extravascular space into the plasma), and iAUC (initial area under the signal intensity-time curve). Regions of interest (ROIs) were drawn around the entire recurrence-suspected contrast-enhanced region. A definitive diagnosis was established at subsequent surgical resection or clinicoradiologic follow-up. The hemodynamic parameters in the contralateral normal white matter, the radiation injury sites, and the tumor recurrent lesions were compared using nonparametric tests. RESULTS: The K(trans), v(e), k(ep), and iAUC values in the normal white matter were significantly different than those in the radiation necrosis and recurrent gliomas (0.01,