An optimized 3T MRI scan protocol to assess iris melanoma with subsequent histopathological verification - A prospective study.

INTRODUCTION: Magnetic resonance imaging (MRI) has demonstrated high levels of tissue contrast, accuracy and reproducibility in evaluating posterior uveal melanoma. Owing to smaller size, the role of MRI in detecting and characterising iris melanoma has not yet been explored. AIMS: To develop a protocol to image iris melanoma and describe the MRI characteristics of histopathological-confirmed iris melanoma. MATERIALS AND METHODS: An optimised MRI protocol, using a 3T MRI scanner and a 32-channel head coil, was developed to image iris tumours. A prospective, single-centre, 12-month study was conducted on all patients with lesions suspicious for iris melanoma. All patients were offered an MRI scan in addition to the standardised clinical procedures. Image quality comparison was made with existing clinical investigations. Iris melanoma characteristics on MRI are described. RESULTS: A successful optimised MRI scan protocol was developed that was able to detect and characterise iris melanoma. One normal participant and five patients with subsequent histopathological-confirmed iris melanoma (n = 6) were recruited. Four patients completed the full MRI sequence. All iris melanoma were detected on at least one T1- or T2-weighted images. When compared to the vitreous, all iris melanomas demonstrated hyper-intensity on T1-weighted images and hypo-intensity on T2-weighted images. On T1-mapping, T1-values of iris melanoma demonstrated an inverse relationship with the degree of tumour pigmentation. CONCLUSIONS: This study highlights an optimised, easily reproducible MRI scan protocol to image iris melanoma. Numerous MR imaging characteristics of iris melanoma are reported for the first time and a potential non-invasive tumour biomarker is described.

Faculty development for strengthening online teaching capability: a mixed-methods study of what staff want, evaluated with Kirkpatrick's model of teaching effectiveness.

Background: Globally, tertiary teachers are increasingly being pushed and pulled into online teaching. While most developments in online education have focused on the student perspective, few studies have reported faculty development (FD) initiatives for increasing online teaching capability and confidence from a staff perspective. Methods: We designed and evaluated FD workshops, using five datasets, and the use of H5P software for interactive online teaching. We used educational theory to design our FD (Mayer multimedia principles, active learning) and evaluated our FD initiatives using the Best Evidence Medical Education (BEME) 2006 modified Kirkpatrick levels. Results: Teaching staff reported that Communities of Practice were important for their learning and emotional support. Uptake and deployment of FD skills depended on the interactivity of FD sessions, their timeliness, and sufficient time allocated to attend and implement. Staff who applied FD learning to their online teaching created interactive learning resources. This content was associated with an increase in student grades, and the roll-out of an institutional site-wide H5P license. Conclusion: This paper demonstrates an effective strategy for upskilling and upscaling faculty development. The use of H5P as a teaching tool enhances student learning. For successful FD, we make four recommendations. These are: provide just-in-time learning and allocate time for FD and staff to create online teaching material; foster supportive communities; offer personalized support; and design hands on active learning.

Compound heterozygous splicing variants expand the genotypic spectrum of EMC1-related disorders.

EMC1 encodes subunit 1 of the endoplasmic reticulum (ER) membrane protein complex (EMC), a transmembrane domain insertase involved in membrane protein biosynthesis. Variants in EMC1 are described as a cause of global developmental delay, hypotonia, cortical visual impairment, and commonly, cerebral atrophy on MRI scan. We report an individual with severe global developmental delay and progressive cerebellar atrophy in whom exome sequencing identified a heterozygous essential splice-site variant in intron-3 of EMC1 (NM_015047.3:c.287-1G>A). Whole genome sequencing (WGS) identified a deep intronic variant in intron-20 of EMC1 (NM_015047.3:c.2588-771C>G) that was poorly predicted by in silico programs to disrupt pre-mRNA splicing. Reverse Transcription-PCR (RT-PCR) revealed stochastic activation of a pseudo-exon associated with the c.2588-771C>G variant and mis-splicing arising from the c.287-1G>A variant. This case highlights the utility of WGS and RNA studies to identify and assess likely pathogenicity of deep intronic variants and expands the genotypic and phenotypic spectrum of EMC1-related disorders.

The Role of Cue-Based Strategies in Skilled Diagnosis Among Pathologists.

OBJECTIVE: This research was designed to test whether behavioral indicators of pathology-related cue utilization were associated with performance on a diagnostic task. BACKGROUND: Across many domains, including pathology, successful diagnosis depends on pattern recognition that is supported by associations in memory in the form of cues. Previous studies have focused on the specific information or knowledge on which medical image expertise relies. The target in this study is the more general ability to identify and interpret relevant information. METHOD: Data were collected from 54 histopathologists in both conference and online settings. The participants completed a pathology edition of the Expert Intensive Skills Evaluation 2.0 (EXPERTise 2.0) to establish behavioral indicators of context-related cue utilization. They also completed a separate diagnostic task designed to examine related diagnostic skills. RESULTS: Behavioral indicators of higher or lower cue utilization were based on the participants' performance across five tasks. Accounting for the number of cases reported per year, higher cue utilization was associated with greater accuracy on the diagnostic task. A post hoc analysis suggested that higher cue utilization may be associated with a greater capacity to recognize low prevalence cases. CONCLUSION: This study provides support for the role of cue utilization in the development and maintenance of skilled diagnosis amongst pathologists. APPLICATION: Pathologist training needs to be structured to ensure that learners have the opportunity to form cue-based strategies and associations in memory, especially for less commonly seen diseases.

Serratia Marcescens Endophthalmitis and Bacteraemia following Complicated Cataract Surgery.

A 93-year-old male presented with left eye pain, fever and loss of vision two days after complicated cataract surgery. A diagnosis of Serratia marcescens endophthalmitis and systemic bacteremia was made after the organism was identified on vitreous and peripheral blood cultures. This case demonstrates that an aggressive intraocular infection can lead to bacteremia.

WGS and RNA Studies Diagnose Noncoding DMD Variants in Males With High Creatine Kinase.

OBJECTIVE: To describe the diagnostic utility of whole-genome sequencing and RNA studies in boys with suspected dystrophinopathy, for whom multiplex ligation-dependent probe amplification and exomic parallel sequencing failed to yield a genetic diagnosis, and to use remnant normal DMD splicing in 3 families to define critical levels of wild-type dystrophin bridging clinical spectrums of Duchenne to myalgia. METHODS: Exome, genome, and/or muscle RNA sequencing was performed for 7 males with elevated creatine kinase. PCR of muscle-derived complementary DNA (cDNA) studied consequences for DMD premessenger RNA (pre-mRNA) splicing. Quantitative Western blot was used to determine levels of dystrophin, relative to control muscle. RESULTS: Splice-altering intronic single nucleotide variants or structural rearrangements in DMD were identified in all 7 families. Four individuals, with abnormal splicing causing a premature stop codon and nonsense-mediated decay, expressed remnant levels of normally spliced DMD mRNA. Quantitative Western blot enabled correlation of wild-type dystrophin and clinical severity, with 0%-5% dystrophin conferring a Duchenne phenotype, 10% ± 2% a Becker phenotype, and 15% ± 2% dystrophin associated with myalgia without manifesting weakness. CONCLUSIONS: Whole-genome sequencing relied heavily on RNA studies to identify DMD splice-altering variants. Short-read RNA sequencing was regularly confounded by the effectiveness of nonsense-mediated mRNA decay and low read depth of the giant DMD mRNA. PCR of muscle cDNA provided a simple, yet informative approach. Highly relevant to genetic therapies for dystrophinopathies, our data align strongly with previous studies of mutant dystrophin in Becker muscular dystrophy, with the collective conclusion that a fractional increase in levels of normal dystrophin between 5% and 20% is clinically significant.

Hereditary diffuse gastric cancer: updated clinical practice guidelines.

Hereditary diffuse gastric cancer (HDGC) is an autosomal dominant cancer syndrome that is characterised by a high prevalence of diffuse gastric cancer and lobular breast cancer. It is largely caused by inactivating germline mutations in the tumour suppressor gene CDH1, although pathogenic variants in CTNNA1 occur in a minority of families with HDGC. In this Policy Review, we present updated clinical practice guidelines for HDGC from the International Gastric Cancer Linkage Consortium (IGCLC), which recognise the emerging evidence of variability in gastric cancer risk between families with HDGC, the growing capability of endoscopic and histological surveillance in HDGC, and increased experience of managing long-term sequelae of total gastrectomy in young patients. To redress the balance between the accessibility, cost, and acceptance of genetic testing and the increased identification of pathogenic variant carriers, the HDGC genetic testing criteria have been relaxed, mainly through less restrictive age limits. Prophylactic total gastrectomy remains the recommended option for gastric cancer risk management in pathogenic CDH1 variant carriers. However, there is increasing confidence from the IGCLC that endoscopic surveillance in expert centres can be safely offered to patients who wish to postpone surgery, or to those whose risk of developing gastric cancer is not well defined.

An Unusual Presentation of Pediatric Conjunctival Mucosa-Associated Lymphoid Tissue Lymphoma.

Ocular adnexal mucosa-associated lymphoid tissue (MALT) lymphoma is uncommon in the pediatric population. Initial misdiagnosis is common and there is lacking consensus regarding the optimal approach to treatment. Herein, we report an atypical presentation of pediatric conjunctival MALT lymphoma and review the presentation and management of this rare condition.

Computer Aided Classification of Neuroblastoma Histological Images Using Scale Invariant Feature Transform with Feature Encoding.

Neuroblastoma is the most common extracranial solid malignancy in early childhood. Optimal management of neuroblastoma depends on many factors, including histopathological classification. Although histopathology study is considered the gold standard for classification of neuroblastoma histological images, computers can help to extract many more features some of which may not be recognizable by human eyes. This paper, proposes a combination of Scale Invariant Feature Transform with feature encoding algorithm to extract highly discriminative features. Then, distinctive image features are classified by Support Vector Machine classifier into five clinically relevant classes. The advantage of our model is extracting features which are more robust to scale variation compared to the Patched Completed Local Binary Pattern and Completed Local Binary Pattern methods. We gathered a database of 1043 histologic images of neuroblastic tumours classified into five subtypes. Our approach identified features that outperformed the state-of-the-art on both our neuroblastoma dataset and a benchmark breast cancer dataset. Our method shows promise for classification of neuroblastoma histological images.

Convolutional Deep Belief Network with Feature Encoding for Classification of Neuroblastoma Histological Images.

BACKGROUND: Neuroblastoma is the most common extracranial solid tumor in children younger than 5 years old. Optimal management of neuroblastic tumors depends on many factors including histopathological classification. The gold standard for classification of neuroblastoma histological images is visual microscopic assessment. In this study, we propose and evaluate a deep learning approach to classify high-resolution digital images of neuroblastoma histology into five different classes determined by the Shimada classification. SUBJECTS AND METHODS: We apply a combination of convolutional deep belief network (CDBN) with feature encoding algorithm that automatically classifies digital images of neuroblastoma histology into five different classes. We design a three-layer CDBN to extract high-level features from neuroblastoma histological images and combine with a feature encoding model to extract features that are highly discriminative in the classification task. The extracted features are classified into five different classes using a support vector machine classifier. DATA: We constructed a dataset of 1043 neuroblastoma histological images derived from Aperio scanner from 125 patients representing different classes of neuroblastoma tumors. RESULTS: The weighted average F-measure of 86.01% was obtained from the selected high-level features, outperforming state-of-the-art methods. CONCLUSION: The proposed computer-aided classification system, which uses the combination of deep architecture and feature encoding to learn high-level features, is highly effective in the classification of neuroblastoma histological images.

Congenital Titinopathy: Comprehensive characterization and pathogenic insights.

OBJECTIVE: Comprehensive clinical characterization of congenital titinopathy to facilitate diagnosis and management of this important emerging disorder. METHODS: Using massively parallel sequencing we identified 30 patients from 27 families with 2 pathogenic nonsense, frameshift and/or splice site TTN mutations in trans. We then undertook a detailed analysis of the clinical, histopathological and imaging features of these patients. RESULTS: All patients had prenatal or early onset hypotonia and/or congenital contractures. None had ophthalmoplegia. Scoliosis and respiratory insufficiency typically developed early and progressed rapidly, whereas limb weakness was often slowly progressive, and usually did not prevent independent walking. Cardiac involvement was present in 46% of patients. Relatives of 2 patients had dilated cardiomyopathy. Creatine kinase levels were normal to moderately elevated. Increased fiber size variation, internalized nuclei and cores were common histopathological abnormalities. Cap-like regions, whorled or ring fibers, and mitochondrial accumulations were also observed. Muscle magnetic resonance imaging showed gluteal, hamstring and calf muscle involvement. Western blot analysis showed a near-normal sized titin protein in all samples. The presence of 2 mutations predicted to impact both N2BA and N2B cardiac isoforms appeared to be associated with greatest risk of cardiac involvement. One-third of patients had 1 mutation predicted to impact exons present in fetal skeletal muscle, but not included within the mature skeletal muscle isoform transcript. This strongly suggests developmental isoforms are involved in the pathogenesis of this congenital/early onset disorder. INTERPRETATION: This detailed clinical reference dataset will greatly facilitate diagnostic confirmation and management of patients, and has provided important insights into disease pathogenesis. Ann Neurol 2018;83:1105-1124.

Nemaline myopathy and distal arthrogryposis associated with an autosomal recessive TNNT3 splice variant.

A male neonate presented with severe weakness, hypotonia, contractures and congenital scoliosis. Skeletal muscle specimens showed marked atrophy and degeneration of fast fibers with striking nemaline rods and hypertrophy of slow fibers that were ultrastructurally normal. A neuromuscular gene panel identified a homozygous essential splice variant in TNNT3 (chr11:1956150G > A, NM_006757.3:c.681+1G > A). TNNT3 encodes skeletal troponin-Tfast and is associated with autosomal dominant distal arthrogryposis. TNNT3 has not previously been associated with nemaline myopathy (NM), a rare congenital myopathy linked to defects in proteins associated with thin filament structure and regulation. cDNA studies confirmed pathogenic consequences of the splice variant, eliciting exon-skipping and intron retention events leading to a frameshift. Western blot showed deficiency of troponin-Tfast protein with secondary loss of troponin-Ifast . We establish a homozygous splice variant in TNNT3 as the likely cause of severe congenital NM with distal arthrogryposis, characterized by specific involvement of Type-2 fibers and deficiency of troponin-Tfast .

Rare Case of Hepatic Gaucheroma in a Child on Enzyme Replacement Therapy.

BACKGROUND: We present a 6 year old boy with type I Gaucher treated from 16 months with ERT, developing focal Gaucheroma in the liver at 3.5 years. CASE: The subject presented at 13 months of age with anaemia, thrombocytopenia and hepatosplenomegaly. Gaucher disease was confirmed by leucocyte enzyme assay. A homozygous change: c.1193G>A (p.Arg398Gln) in the GBA gene was identified. He had normal neurology with normal saccades. Imiglucerase was administered at 60 IU/kg/fortnight from 15 months as per Australian regulations with good clinical response. At 3.5 years hepatic ultrasound demonstrated a nodular cystic lesion measuring 7 × 5.3 × 5.1 cm in the right lobe of liver, confirmed on MRI. Biopsy demonstrated acellular hyaline necrosis, portal-portal bridging fibrosis and nodules of Gaucher cells. Cystic fluid comprised necrotic debris and Gaucher cells. Further evaluation over 18 months including repeat MRI, biopsy, alpha-fetoprotein monitoring and whole-body FDG-Pet scan demonstrate no malignancy. CONCLUSION: GD is the most common lysosomal storage disorder. The aetiology, natural history and optimal management strategy of rare Gaucheroma in paediatric cases has not been defined particularly in regards to malignancy risk.

Congenital lobar emphysema: diagnostic and therapeutic challenges.

Congenital lobar emphysema (CLE), a rare condition that usually presents in the neonatal period, can be a diagnostic and therapeutic challenge for the treating clinician. If unrecognised, it is a significant risk at the time of anaesthetic induction. We describe a case of CLE in a 3-month-old boy who was initially treated for suspected aspiration pneumonia at the referring hospital. We highlight the importance of careful consideration of common childhood respiratory illness as well as pneumothorax in the differential diagnosis, and the significance of appropriate preoperative anaesthetic management. We also emphasise the importance of acknowledging a mother's concerns when taking a paediatric history.

ß-HCG Elevation in Wilms Tumor: An Uncommon Presentation.

Wilms tumor (nephroblastoma) is a readily diagnosed common abdominal tumor in children. Rarely, it may present with factors that may confound the diagnosis. We report a 6-year-old female child who presented with a rapidly growing and invasive abdominal mass with the histopathologic features of Wilms tumor associated with an elevated serum beta human chorionic gonadotropin, which has not been previously reported in this condition.

Aganglionosis with the absence of hypertrophied nerve fibres predicts disease proximal to rectosigmoid colon.

PURPOSE: The gold standard for the diagnosis of Hirschsprung's disease (HSCR) is the pathologic evaluation of a rectal biopsy that demonstrates the absence of ganglion cells and nerve fibre hypertrophy. However, it has been frequently reported that hypertrophic nerves may not be present in some variants like long-segment HSCR, total colonic aganglionosis, premature and very young infants. The aim of this study was to determine this association. METHODS: We performed a retrospective review of the HSCR database at our tertiary care children's hospital from 2000 to 2013. In order to analyse the relationship between the diameter of the nerve fibres and the level of aganglionosis, we classified the patient sample into two groups-fibres ≤40 and >40 µm. The groups were statistically compared with P < 0.05 being significant. RESULTS: Rectal biopsies of 92 patients confirmed as HSCR with definitive operation performed at the same institution were reviewed. The mean nerve diameter was 50.1 µm (range 20-87.5 µm). Nerve fibre diameter ≤40 µm was predictive of transition zone above the sigmoid colon. A specificity of 77.3 % and a likelihood ratio of 2.03 supported this perception. No correlation was noted between nerve fibre diameter and gestational age at birth, birth weight or age at biopsy. CONCLUSION: The absence of nerve fibre hypertrophy in the presence of aganglionosis on rectal biopsy specimens is predictive of long-segment HSCR.

Risk of malignancy for each Bethesda class in pediatric thyroid nodules.

PURPOSE: The Bethesda classification for cytology is used to classify thyroid nodules into one of six categories, and for each category there is an implied cancer risk and also recommendation for management. Despite lack of data in children, the American thyroid association promotes the use of the same management guidelines as in adults. Our aim was to study the risk of malignancy for each Bethesda class in children with thyroid nodules. METHODOLOGY: We included all patients ≤18years of age that had underwent a thyroid fine needle aspiration (FNA) at one of two centers between January 1998 and July 2013. FNA results were reclassified according to the Bethesda criteria. Histological, repeat cytological, radiological and clinical follow-up were recorded. RESULTS: Fifty-six patients (66 nodules) underwent FNB. Mean age was 13.6 years. Numbers of nodules reported as BI-BVI were 7, 38, 11, 4, 3 and 3, respectively. Follow-up was achieved for 55 (83%) nodules. Twelve (18%) nodules were malignant by histology and revealed papillary (n=7), follicular (n=3) or insular thyroid cancer (n=2), The proportion of nodules with malignancy for BI-BVI was: 0%, 0%, 18%, 100%, 100% and 100%. CONCLUSION: The rate of malignancy in thyroid nodules in children seems to be higher than reported in adults. The Bethesda criteria seem to accurately identify benign nodules, but other categories have a very high rate of malignancy and BIII nodules pose a particular challenge.

Recessive ACTA1 variant causes congenital muscular dystrophy with rigid spine.

Variants in ACTA1, which encodes α-skeletal actin, cause several congenital myopathies, most commonly nemaline myopathy. Autosomal recessive variants comprise approximately 10% of ACTA1 myopathy. All recessive variants reported to date have resulted in loss of skeletal α-actin expression from muscle and severe weakness from birth. Targeted next-generation sequencing in two brothers with congenital muscular dystrophy with rigid spine revealed homozygous missense variants in ACTA1. Skeletal α-actin expression was preserved in these patients. This report expands the clinical and histological phenotype of ACTA1 disease to include congenital muscular dystrophy with rigid spine and dystrophic features on muscle biopsy. This represents a new class of recessive ACTA1 variants, which do not abolish protein expression.