Multifocal Medulloblastoma in an Adult Patient: Description of a Rare Presentation and Review of the Literature.

Medulloblastoma is an embryonal neuroepithelial tumor that affects mainly childhood and more rarely adults. Medulloblastoma occurring as multiple nodules at diagnosis is a rare and tricky presentation. Here, we describe the case of a previously healthy 47-year-old woman with multiple posterior fossa cerebellar tumors. Histological, immunohistochemical, and molecular analyses were performed to best characterize the two excised lesions. The histopathological analysis revealed different variants of medulloblastoma in the excised nodules, one being extensive nodularity, rare in adults, and the other desmoplastic/nodular with areas of anaplasia. Immunostains and molecular analysis classified both nodules as SHH medulloblastoma. Adult medulloblastoma is extremely rare. Important differences exist between adult medulloblastoma and medulloblastoma arising in children and infants. Such differences are in location, distribution of histological variants and of molecular subgroups, survival rates, and therapeutic options. An extensive morphological and molecular characterization of such rare tumors is necessary to choice the best-tailored therapy.

Molecular features and clinical outcomes in surgically treated low-grade diffuse gliomas in patients over the age of 60.

PURPOSE: WHO grade II gliomas are uncommon in patients over the age of 60, and there is a lack in consensus regarding their management. We present molecular tumor characteristics as well as clinical outcomes in patients over the age of 60 undergoing surgical resection of a WHO grade II glioma. METHODS: After receiving IRB approval, patients were identified through the UCSF Brain Tumor Center. Pathologic diagnosis was completed using WHO 2016 grading criteria. RESULTS: Twenty-six patients with a mean age of 66 years met inclusion criteria with a median follow-up of 5.2 years. Diagnoses included diffuse astrocytoma IDH-mutant (19.2%), diffuse astrocytoma IDH-wildtype (26.9%), Oligodendroglioma IDH-mutant and 1p/19q-codeleted (50%), and a rare case of mixed oligoastrocytoma (3.9%). 66% of astrocytoma IDH-wildtype tumors possessed TERT mutation. Median extent of resection was 75.4%. Progression-free (PFS) and overall survival (OS) were 23.5 and 62.6 months, respectively. Shorter PFS was associated with the astrocytoma IDH-wildtype subtype despite similar extent of resection and adjuvant treatment rates compared to the other subtypes. OS did not differ between subtypes. Malignant transformation and death were associated with larger preoperative and residual tumor volume. CONCLUSIONS: Older patients with diffuse gliomas may safely undergo aggressive treatment with surgical resection and adjuvant therapy. Elderly patients with low grade gliomas have worse clinical outcomes compared to their younger counterparts. This may be due to an increased frequency of diffuse astrocytoma IDH-wildtype tumors in this age group.

Subcortical stimulation mapping of descending motor pathways for perirolandic gliomas: assessment of morbidity and functional outcome in 702 cases.

OBJECTIVE: Herein, the authors report their experience with intraoperative stimulation mapping to locate the descending subcortical motor pathways in patients undergoing surgery for hemispheric gliomas within or adjacent to the rolandic cortex, with particular description of the morbidity and functional outcomes associated with this technique. METHODS: This is a retrospective analysis of patients who, in the period between 1997 and 2016, had undergone resection of hemispheric perirolandic gliomas within or adjacent to descending motor pathways. Data regarding intraoperative stimulation mapping and patient postoperative neurological status were collected. RESULTS: Of 702 patients, stimulation mapping identified the descending motor pathways in 300 cases (43%). A new or worsened motor deficit was seen postoperatively in 210 cases (30%). Among these 210 cases, there was improvement in motor function to baseline levels by 3 months postoperatively in 161 cases (77%), whereas the deficit remained in 49 cases (23%). The majority (65%) of long-term deficits (persisting beyond 3 months) were mild or moderate (antigravity strength or better). On multivariate analysis, patients in whom the subcortical motor pathways had been identified with stimulation mapping during surgery were more likely to develop an additional and/or worsened motor deficit postoperatively than were those in whom the subcortical pathways had not been found (45% vs 19%, respectively, p < 0.001). This difference remained when considering the likelihood of a long-term deficit (i.e., persisting > 3 months; 12% vs 3.2%, p < 0.001). A higher tumor grade and the presence of a preoperative motor deficit were also associated with higher rates of motor deficits persisting long-term. A region of restricted diffusion adjacent to the resection cavity was seen in 20 patients with long-term deficits (41%) and was more common in cases in which the motor pathways were not identified (69%). Long-term deficits that occur in settings in which the subcortical motor pathways are not identified seem in large part due to ischemic injury to descending tracts. CONCLUSIONS: Stimulation mapping allows surgeons to identify the descending motor pathways during resection of tumors in perirolandic regions and to attain an acceptable rate of morbidity in these high-risk cases.

Predictive value of intraoperative 5-aminolevulinic acid-induced fluorescence for detecting bone invasion in meningioma surgery.

OBJECT: Bone invasion is a major concern in meningioma surgery, since it is predictive of the recurrence of cranial involvement, morbidity, and mortality. Bone invasion has been reported in 20%-68% of studies with histopathologically confirmed data. Unfortunately, radical resection of bone invasion remains challenging. The aim of this study was to assess the role of 5-aminolevulinic acid (5-ALA) fluorescence in guiding the resection of bone-invading meningiomas. To this purpose, the sensitivity, specificity, and positive and negative predictive values of 5-ALA in detecting meningioma bone invasion were evaluated. METHODS: Data from 12 patients affected by bone-invading meningiomas (7 with skull base and 5 with convexity meningiomas) who had undergone surgery with the assistance of 5-ALA fluorescence and neuronavigation between July 2012 and March 2013 at the Department of Neurosurgery of Padua were retrospectively analyzed. To evaluate the sensitivity and specificity of 5-ALA fluorescence in detecting meningioma tissue, a pathologist analyzed 98 surgical bone samples under blue light, according to different fluorescence patterns. Magnetic resonance images and CT scans were obtained pre- and postoperatively to determine the extent of bone invasion resection. RESULTS: The rate of 5-ALA-induced fluorescence of both tumor and bone invasion was 100%. Based on the pathological examination of bone specimens, 5-ALA presented a sensitivity of 89.06% (95% CI 81.41%-96.71%) and a specificity of 100% in detecting meningioma bone invasion, while the positive and negative predictive values were 100% and 82.93% (95% CI 71.41%-94.45%), respectively. At the postoperative stage, MRI did not detect cases of meningioma bone invasion, whereas CT scans revealed residual hyperostosis in 2 cases. CONCLUSIONS: In summary, 5-ALA fluorescence represents a suitable and reliable technique for identifying and removing bone infiltration by meningiomas. However, further studies are needed to prove the clinical consequences of this promising technique in a larger population.

Microsurgical clipping of intracranial aneurysms assisted by green indocyanine videoangiography (ICGV) and ultrasonic perivascular microflow probe measurement.

OBJECTIVES: The purpose of this work is to assess the surgical and clinical outcome of intracranial aneurysm clipping performed combining the assistance of green indocyanine videoangiography (ICGV) and ultrasonic perivascular microflow probe. PATIENTS AND METHODS: Data from patients affected with intracranial aneurysms who underwent microsurgical clipping assisted by both techniques between May 2012 and April 2013 were retrospectively evaluated. RESULTS: 26 patients with 34 aneurysms (25 unruptured) were enrolled. In a total of 11 aneurysms (32%), the vascular clip needed repositioning, since either the post-clipping microprobe assessment detected a significant flow reduction of the explored vessels (8 cases, 23%) or ICGV identified a residual non-obliterated aneurysm (3 cases, 9%). A second clip repositioning was required in 3 cases (9%) because of dome remnant showed with ICGV. In all cases, final microprobe and ICGV assessments showed a complete exclusion of the aneurysm, without evidence of vascular flow impairment. Postoperatively, 1 patient (3%) presented a residual neck aneurysm. No permanent morbidity was reported. CONCLUSION: With the limits of our small case series, our results testify that the presented approach may provide high exclusion rate in the treatment of cerebral aneurysm with very low morbidity in selected patients.