Search

Pituitary neuroendocrine tumours (PitNETs) associated with paragangliomas or phaeochromocytomas are rare. SDHx variants are estimated to be associated with 0.3–1.8% of PitNETs. Only a few case reports have documented the association with MAX variants. Prolactinomas are the most common PitNETs occurring in patients with SDHx variants, followed by somatotrophinomas, clinically non-functioning tumours and corticotrophinomas. One pituitary carcinoma has been described. SDHC, SDHB and SDHA mutations are inherited in an autosomal dominant fashion and tumorigenesis seems to adhere to Knudson’s two-hit hypothesis. SDHD and SDHAF2 mutations most commonly have paternal inheritance. Immunohistochemistry for SDHB or MAX and loss of heterozygosity analysis can support the assessment of pathogenicity of the variants. Metabolomics is promising in the diagnosis of SDHx-related disease. Future research should aim to further clarify the role of SDHx and MAX variants or other genes in the molecular pathogenesis of PitNETs, including pseudohypoxic and kinase signalling pathways along with elucidating epigenetic mechanisms to predict tumour behaviour.

Cardiac valve fibrolipomas are extremely rare. We report a case of a 38-year-old female initially presenting with palpitations and moderate aortic incompetence who was found to have a lipomatous growth of the aortic valve. She underwent aortic valve repair with good postoperative results. Histopathogy verified the lesion as a fibrolipoma. This is the first reported case of fibrolipoma in the aortic valve, whilst aiming to consider repair as a surgical option in young patients with such growths.

Tubular aggregates and cylindrical spirals are 2 distinct ultrastructural abnormalities observed in muscle biopsies that have similar histochemical staining characteristics on light microscopy. Both are found in a wide range of disorders. Recently, a number of genetic mutations have been reported in conditions with tubular aggregates in skeletal muscle. It is widely accepted that tubular aggregates arise from the sarcoplasmic reticulum, but the origin of cylindrical spirals has been less clearly defined. We describe the histopathological features of myopathies with tubular aggregates, including a detailed immunohistochemical analysis of congenital myasthenic syndromes with tubular aggregates due to mutations in GFPT1 and DPAGT1, and myopathies with cylindrical spirals. Our findings support the notion that cylindrical spirals, like tubular aggregates, derive primarily from the sarcoplasmic reticulum; however, immunohistochemistry indicates that different molecular components of the sarcoplasmic reticulum may be involved and can be used to distinguish between these different inclusions. The immunohistochemical differences may also help to guide genetic testing.

Objective To characterize the phenotype of patients with symptoms of periodic paralysis (PP) and ryanodine receptor (RYR1) gene mutations. Methods Cases with a possible diagnosis of PP but additional clinicopathologic findings previously associated with RYR1-related disorders were referred for a tertiary neuromuscular clinical assessment in which they underwent detailed clinical evaluation, including neurophysiologic assessment, muscle biopsy, and muscle MRI. Genetic analysis with next-generation sequencing and/or targeted Sanger sequencing was performed. Results Three cases with episodic muscle paralysis or weakness and additional findings compatible with a RYR1-related myopathy were identified. The McManis test, used in the diagnosis of PP, was positive in 2 of 3 cases. Genetic analysis of known PP genes was negative. RYR1 analysis confirmed likely pathogenic variants in all 3 cases. Conclusions RYR1 mutations can cause late-onset atypical PP both with and without associated myopathy. Myalgia and cramps are prominent features. The McManis test may be a useful diagnostic tool to indicate RYR1-associated PP. We propose that clinicopathologic features suggestive of RYR1-related disorders should be sought in genetically undefined PP cases and that RYR1 gene testing be considered in those in whom mutations in SCN4A, CACNA1S, and KCNJ2 have already been excluded.

Inclusion body myositis (IBM) is the commonest acquired myopathy in individuals aged over 50 years. The first description of a patient with IBM was published in 1967. Despite much research into the illness, our understanding is far from complete and IBM remains an enigmatic and often misdiagnosed condition for which there is currently no effective drug treatment. However, new pathological findings, the recent identification of muscle-specific serum auto-antibodies and the increasing use of MRI in patients with IBM are important advances that may lead to earlier diagnosis and improved understanding of the disease. The purpose of this review is to provide an update on the scientific developments in IBM with particular emphasis on current and future clinical trials.

Mutations in Bcl-2 associated athanogene-3 (BAG3) are a rare cause of myofibrillar myopathy, characterised by rapidly progressive proximal and axial myopathy, cardiomyopathy and respiratory compromise. Neuropathy has been documented neurophysiologically in previously reported cases of BAG3-associated myofibrillar myopathy and in some cases giant axons were observed on nerve biopsies; however, neuropathy was not thought to be a dominant feature of the disease. In the context of inherited neuropathy, giant axons are typically associated with autosomal recessive giant axonal neuropathy caused by gigaxonin mutations but have also been reported in association with NEFL- and SH3TC2-associated Charcot-Marie-Tooth disease. Here, we describe four patients with heterozygous BAG3 mutations with clinical evidence of a sensorimotor neuropathy, with predominantly axonal features on neurophysiology. Three patients presented with a significant neuropathy. Muscle magnetic resonance imaging (MRI) in one patient revealed mild to moderate atrophy without prominent selectivity. Examination of sural nerve biopsies in two patients demonstrated giant axons. This report confirms the association of giant axonal neuropathy with BAG3-associated myofibrillar myopathy, and highlights that neuropathy may be a significant feature.

Available treatments for glioma have limited effectiveness rendering this a disease of poor clinical outcome. Gene expression profiling can uncover the biological mechanisms underlying disease, information that is crucial for drug development or repurposing. RNA sequencing (RNA-seq) is routinely used to assess gene expression but costs remain high. Whilst sample multiplexing reduces RNA-seq costs, the lowered cDNA sequencing depth of multiplexed samples may hinder accurate differential gene expression detection. The impact of sequencing depth alteration on RNA-seq-based downstream analyses such as gene expression connectivity mapping is not known. Connectivity mapping is a method used to identify potential therapeutic compounds for drug repurposing. In this study, published RNA-seq from brain tumour (glioma) patients were analysed and assembled into two gene signature contrasts for astrocytoma disease progression (WHO Grade II-III; III-IV). Gene signatures were subsampled to simulate sequencing depth alterations and analysed in connectivity mapping to investigate target compound robustness. Data loss to gene signatures led to the loss, gain and consistent identification of significant connections to target compounds. The most accurate gene signature contrast with consistent patient gene expression profiles was more resilient to data loss and identified robust target compounds. Target compounds lost included candidate compounds of potential clinical utility in glioma (e.g. Suramin, Dasatinib). Lost connections may have been linked to low abundance genes in the gene signature that closely characterised the disease phenotype. Consistently identified connections may have related to highly expressed abundant genes that were ever-present in gene signatures, despite data reductions. Potential noise surrounding findings included false positive connections that were gained as a result of gene signature modification with data loss. Findings highlight the necessity for gene signature accuracy for connectivity mapping, which should improve the clinical utility of future target compounds identified for drug repurposing.

BACKGROUND: Gene expression profiling can uncover biological mechanisms underlying disease and is important in drug development. RNA-seq is routinely used to assess gene expression but costs remain high. Sample multiplexing reduces RNA-seq costs, however, multiplexed samples have lower cDNA sequencing depth, which can hinder accurate differential gene expression detection. The impact of sequencing depth alteration on RNA-seq-based downstream analyses such as gene expression connectivity mapping is not known, where connectivity mapping can be used to identify potential therapeutic compounds for repurposing. MATERIAL AND METHODS: In this study, published RNA-seq profiles from brain tumour (glioma) patients were assembled into two disease progression gene signature contrasts for astrocytoma. Available treatments for glioma have limited effectiveness rendering this a disease of poor clinical outcome. Gene signatures were subsampled to simulate sequencing alterations and analysed in connectivity mapping to investigate target compound robustness. RESULTS: Data loss to gene signatures led to the loss, gain and consistent identification of significant connections. The most accurate gene signature contrast with consistent patient gene expression profiles was more resilient to data loss and identified robust target compounds. Target compounds lost included candidate compounds of potential clinical utility in glioma (e.g. Suramin, Dasatinib). Lost connections may have been linked to low abundance genes in the gene signature that closely characterised the disease phenotype. Consistently identified connections may have been related to highly expressed abundant genes that were ever-present in gene signatures, despite data reductions. Potential noise surrounding findings included false positive connections that were gained as a result of gene signature modification with data loss. CONCLUSION: Findings highlight the necessity for gene signature accuracy for connectivity mapping, which should improve the clinical utility of future target compound discoveries.

We report a rare case of myofasciitis and meningitis with deafness caused by systemic enterovirus infection in the setting of hypogammaglobulinaemia induced by rituximab. Whilst effective and generally safe, anti- CD 20 antibody therapy is increasingly recognised to result in unusual infectious complications to be considered in a treated patient presenting with neurological symptoms. These cases may pose diagnostic difficulties and can have atypical presentations. We present this rare complication of rituximab therapy, with histopathological confirmation of myofasciitis. In the older literature, enterovirus associated myofasciitis may have erroneously been termed dermatomyositis and we review the literature to demonstrate this important nosological point.

Endometriosis is a common condition in women of reproductive age and has a known propensity to involve abdominal wall scars. The authors report 2 cases of endometriosis presenting as mass lesions involving the abdominal wall at the site of insertion of ventriculoperitoneal and lumboperitoneal shunts. In both cases, there was clinical evidence of shunt compromise. Endometriosis involving the site of shunt insertion is an extremely rare phenomenon with, as far as the authors are aware, only a single previously reported case. However, it should be considered in the differential diagnosis when a mass develops at a shunt site in a woman of reproductive age.