Faculty Bibliography

BACKGROUND:Chordomas are rare, notochord-derived neoplasms. Of these tumors, intradural chordomas are exceedingly rare. Most occur within the prepontine, parasellar, or other midline intradural locations. An intradural chordoma arising from the cerebellopontine angle has not been described previously. CASE REPORT/METHODS:We describe the first case of an intradural chordoma originating from the left cerebellopontine angle resected over the course of 2 operations. CONCLUSIONS:Intradural chordomas are rare and can arise anywhere in the posterior fossa. Lack of bony involvement on computed tomography and magnetic resonance imaging are indicative of this pathology when there is also a lack of markers indicating the presence of more common cerebellopontine angle tumors. Treatment goals should include gross total resection and possible radiation therapy.

This report describes unique presentations of inclusion body myositis (IBM) in two unrelated patients, one male and one female, with genetically and histologically confirmed fragile X-associated tremor/ataxia syndrome (FXTAS). We summarize overlapping symptoms between two disorders, clinical course, and histopathological analyses of the two patients with FXTAS and sporadic IBM, clinically defined per diagnostic criteria of the European Neuromuscular Centre. In case 1, a post-mortem analysis of available brain and muscle tissues is also described. Histopathological features (rimmed vacuoles) consistent with clinically defined IBM were detected in both presented cases. Postmortem testing in case 1 revealed the presence of an FMR1 premutation allele of 60 CGG repeats in both brain and skeletal muscle samples. Case 2 was a premutation carrier with 71 CGG repeats who had a son with FXS. Given that FXTAS is associated with immune-mediated disorders among premutation carriers, it is likely that the pathogeneses of IBM and FXTAS are linked. This is, to our knowledge, the first report of these two conditions presenting together, which expands our understanding of clinical symptoms and unusual presentations in patients with FXTAS. Following detection of a premutation allele of the FMR1 gene, FXTAS patients with severe muscle pain should be assessed for IBM.

BRAF protein is a serine/threonine kinase with 766 amino acids. Approximately 15% of human cancers harbor BRAF mutations as well as other BRAF anomalies (amplifications, fusions). Somatic mutations mainly occur in the catalytic kinase domain (CR3), and the predominant mutation is p.V600E which is the substitution of glutamic acid (E) for valine (V) as result of a mutation at codon 600 of the kinase domain. To our knowledge, the vast majority of the cancers have non-germline BRAF mutations. Here we describe a case of a 60-year-old female with a history of hairy cell leukemia (HCL) who presented with aphasia and forgetfulness. A follow-up Brain CT scan showed three distinct brain lesions which were found to be diagnostic of melanoma (confirmed by immunohistochemistry) with no evidence of a concurrent brain involvement by a B-cell neoplasm. Molecular studies confirmed the same BRAF p.V600E mutation in both malignancies (hairy cell leukemia and melanoma). Thereafter the patient was started on BRAF inhibitor treatment and is now symptom-free after one year of follow up. Having two concurrent malignancies with a shared BRAF mutation is extremely rare and makes this an excellent example of a genomic marker-driven treatment in two histologically and immunophenotypically distinct tumors.

This is a report of FMR1 premutation with Prader-Willi phenotype (PWP) and FXTAS. Although the PWP is common in fragile X syndrome (FXS), it has never been described in someone with the premutation. The patient presented intranuclear inclusions, severe obesity, hyperphagia, and ADHD symptoms, typical of the PWP in FXS. In addition, the autopsy revealed multiple architectural cortical abnormalities.

Centronuclear myopathy (CNM) is a group of rare genetic muscle disorders characterized by muscle fibers with centrally located nuclei. The most common forms of CNM have been attributed to X-linked recessive mutations in the MTM1 gene; autosomal-dominant mutations in the DNM2 gene-encoding dynamin-2, the BIN1 gene; and autosomal-recessive mutations in BIN1, RYR1, and TTN genes. Dominant CNM due to DNM2 mutations usually follows a mild clinical course with the onset in adolescence. Currently, around 35 mutations of the DNM2 gene have been identified in CNM; however, the underlying molecular mechanism of DNM2 mutation in the pathology of CNM remains elusive, and the standard clinical characteristics have not yet been defined. Here, we describe the case of a 17-year-old female who presented with proximal muscle weakness along with congenital anomalous pulmonary venous connection (which has not been described in previous cases of CNM), scoliosis, and lung disease without a significant family history. Her creatine kinase level was normal. Histology, special stains, and electron microscope findings on her skeletal muscle biopsy showed CNM with the characteristic features of a DNM2 mutation, which was later confirmed by next-generation sequencing. This case expands the known clinical and pathological findings of CNM with DNM2 gene mutation.

The expression patterns of critical molecular components of Wnt signaling, sFRP3 and DVL3, were investigated in glioblastoma, the most aggressive form of primary brain tumors, with the aim to offer potential biomarkers. The protein expression levels and localizations in tumor tissue were revealed by immunohistochemistry and evaluated by the semiquantitative method and immunoreactivity score. Majority of glioblastomas had moderate expression levels for both DVL3 (52.4%) and sFRP3 (52.3%). Strong expression levels were observed in 23.1% and 36.0% of samples, respectively. DVL3 was localized in cytoplasm in 97% of glioblastomas, of which 44% coexpressed the protein in the nucleus. sFRP3 subcellular distribution showed that it was localized in the cytoplasm in 94% of cases. Colocalization in the cytoplasm and nucleus was observed in 50% of samples. Wilcox test indicated that the domination of the strong signal is in connection with simultaneous localization of DVL3 protein in the cytoplasm and the nucleus. Patients with strong expression of DVL3 will significantly more often have the protein in the nucleus (P = 6.33 × 10^-5). No significant correlation between the two proteins was established, nor were their signal strengths correlated with epidemiological parameters. Our study contributes to better understanding of glioblastoma molecular profile.

Histologic examination of tissues is central to the diagnosis and management of neoplasms and many other diseases, and is a foundational technique for preclinical and basic research. However, commonly used bright-field microscopy requires prior preparation of micrometre-thick tissue sections mounted on glass slides, a process that can require hours or days, that contributes to cost, and that delays access to critical information. Here, we introduce a simple, non-destructive slide-free technique that within minutes provides high-resolution diagnostic histological images resembling those obtained from conventional haematoxylin-and-eosin-histology. The approach, which we named microscopy with ultraviolet surface excitation (MUSE), can also generate shape and colour-contrast information. MUSE relies on ~280-nm ultraviolet light to restrict the excitation of conventional fluorescent stains to tissue surfaces, and it has no significant effects on downstream molecular assays (including fluorescence in situ hybridization and RNA-seq). MUSE promises to improve the speed and efficiency of patient care in both state-of-the-art and low-resource settings, and to provide opportunities for rapid histology in research.

BACKGROUND:Autism is not correlated with any neuropathological hallmark as the brain of autistic individuals lack defined lesions. However, previous investigations have reported cortical heterotopias and local distortion of the cytoarchitecture of the neocortex in some cases of autism. CASE PRESENTATION/METHODS:Our patient was a 40-year-old white woman diagnosed at an early age with autism and mental retardation. Pencil fibers were present within the prefrontal cortex (Brodmann area 47) and its composition resembled that of the underlying white matter region. Pencil fibers encompassed most of the extent of the cortical grey matter and were populated by oligodendrocytes, astrocytes, and microglial cells, but not by neurons. CONCLUSIONS:Here we report a new cytoarchitectural abnormality that has not been previously described in autism. Future pathological examinations should keep in mind the potential presence of pencil fibers within the prefrontal cortex of cases with autism.

Research over the last decade recognized the importance of novel molecular pathways in pathogenesis of intracranial meningiomas. In this review, we focus on human brain tumours meningiomas and the involvement of Wnt signalling pathway genes and proteins in this common brain tumour, describing their known functional effects. Meningiomas originate from the meningeal layers of the brain and the spinal cord. Most meningiomas have benign clinical behaviour and are classified as grade I by World Health Organization (WHO). However, up to 20% histologically classified as atypical (grade II) or anaplastic (grade III) are associated with higher recurrent rate and have overall less favourable clinical outcome. Recently, there is emerging evidence that multiple signalling pathways including Wnt pathway contribute to the formation and growth of meningiomas. In the review we present the synopsis on meningioma histopathology and genetics and discuss our research regarding Wnt in meningioma. Epithelial-to-mesenchymal transition, a process in which Wnt signalling plays an important role, is shortly discussed.