Metastatic neuroblastoma in fertility preservation biopsy of clinically normal testis: a case report.

RESEARCH QUESTION: Is there potential for the detection of neuroblastoma malignancy in testicular tissue extracted for fertility preservation for prepubertal boys at the time of tissue freezing? DESIGN: This is a case report. RESULTS: A boy was diagnosed with primary localized left adrenal neuroblastoma, with complete resection of the tumour. During 6 months' surveillance, he developed a relapse in the left para-renal region with progression of molecular and chromosomal features into undifferentiated neuroblastoma. Before highly gonadotoxic treatment, testicular biopsy for fertility preservation was taken, from a clinically normal testis. Histopathological examination of the testicular biopsy revealed metastatic neuroblastoma. CONCLUSIONS: Metastatic neuroblastoma detected histologically in a clinically normal testis highlights the importance of routine histological examination at the time of testicular cryopreservation. The histological evaluation of gonadal tissue for potential malignant contamination before freezing should be mandatory, regardless of the malignancy diagnosis. Advances in sensitive molecular detection and in-vitro maturation are critically required to decrease future risk of disease recurrence in both solid and haematological malignancies.

Immunohistochemical and nanoString-Based Subgrouping of Clinical Medulloblastoma Samples.

The diagnosis of medulloblastoma incorporates the histologic and molecular subclassification of clinical medulloblastoma samples into wingless (WNT)-activated, sonic hedgehog (SHH)-activated, group 3 and group 4 subgroups. Accurate medulloblastoma subclassification has important prognostic and treatment implications. Immunohistochemistry (IHC)-based and nanoString-based subgrouping methodologies have been independently described as options for medulloblastoma subgrouping, however have not previously been directly compared. We describe our experience with nanoString-based subgrouping in a clinical setting and compare this with our IHC-based results. Study materials included FFPE tissue from 160 medulloblastomas. Clinical data and tumor histology were reviewed. Immunohistochemical-based subgrouping using ß-catenin, filamin A and p53 antibodies and nanoString-based gene expression profiling were performed. The sensitivity and specificity of IHC-based subgrouping of WNT and SHH-activated medulloblastomas was 91.5% and 99.54%, respectively. Filamin A immunopositivity highly correlated with SHH/WNT-activated subgroups (sensitivity 100%, specificity 92.7%, p < 0.001). Nuclear ß-catenin immunopositivity had a sensitivity of 76.2% and specificity of 99.23% for detection of WNT-activated tumors. Approximately 23.8% of WNT cases would have been missed using an IHC-based subgrouping method alone. nanoString could confidently predict medulloblastoma subgroup in 93% of cases and could distinguish group 3/4 subgroups in 96.3% of cases. nanoString-based subgrouping allows for a more prognostically useful classification of clinical medulloblastoma samples.

Normal Gamma Glutamyl Transferase Levels at Presentation Predict Poor Outcome in Biliary Atresia.

OBJECTIVES: Gamma-glutamyl transferase levels (GGT) are typically elevated in biliary atresia (BA), but normal GGT levels have been observed. This cohort of "normal GGT" BA has neither been described nor has the prognostic value of GGT level on outcomes in BA. We aimed to describe outcomes of a single-centre Australian cohort of infants with BA and assess the impact of GGT level at presentation on outcomes in BA. METHODS: Infants diagnosed with BA between 1991 and 2017 were retrospectively analysed. Outcomes were defined as survival with native liver, liver transplantation (LT), and death. Patients were categorized into normal (<200I U/L) or high GGT groups based on a mean of 3 consecutive GGT values done before Kasai portoenterostomy (KPE). Baseline parameters, age at surgery, clearance of jaundice (COJ), and outcomes were compared between the 2 groups. RESULTS: One hundred thirteen infants underwent KPE at median 61 (30-149) days. At a median follow-up of 14.2 (0.9-26.3) years, 35% (39/113) patients were surviving with native liver, 55% (62/113) underwent LT and 11% (12/113) died pretransplant. 12.3% (14/113) patients had normal GGT. Age at KPE and time to COJ were similar between normal and high GGT groups. Normal GGT group had shorter time from KPE to LT (11 vs 18 months, P = 0.02), underwent LT at a younger age (14 vs 20 months, P = 0.04), and had poorer transplant-free survival (P = 0.04) than high GGT group. CONCLUSIONS: 12.3% of infants with BA had normal GGT levels at diagnosis. Low GGT levels at presentation in BA was associated with a poorer outcome.

Sporadic Creutzfeldt-Jakob Disease in a Young Girl With Unusually Long Survival.

Creutzfeldt-Jakob disease (CJD) is a rapidly progressive, fatal degenerative encephalopathy caused by a pathologically altered form of the prion protein (PrP). CJD is rare, with 1 and 2 cases per million per year reported in the general population, mostly in individuals over 50 years of age. It is almost unknown in the pediatric population. Sporadic CJD with unusually long survival (sCJD-LS), an unusual clinicopathological variant of CJD, has been described mostly in Japanese patients. We present here the first case report of pediatric CJD-LS occurring sporadically in a teenage girl of European descent, with initially rapid neurocognitive decline followed by a prolonged (∼10 years) clinical course. Neuropathological findings at autopsy included generalized cerebral and cerebellar atrophy with relative sparing of the hippocampi, cerebral and cerebellar white and gray matter involvement, minimal spongiform change, PrP deposits in the neocortex, striatum and cerebellum by immunohistochemistry, and protease-resistant PrP by Western immunoblot. With its longer disease duration and atypical manifestations of white matter loss, CJD-LS can be clinically mistaken for other neurodegenerative diseases, or in the pediatric setting for metabolic/genetic conditions. This case clearly demonstrates that with rapid-onset encephalopathy, prion disease should be carefully considered, even in younger patients with slower disease progression.

FHL1 reduces dystrophy in transgenic mice overexpressing FSHD muscular dystrophy region gene 1 (FRG1).

Facioscapulohumeral muscular dystrophy (FSHD) is an autosomal-dominant disease with no effective treatment. The genetic cause of FSHD is complex and the primary pathogenic insult underlying the muscle disease is unknown. Several disease candidate genes have been proposed including DUX4 and FRG1. Expression analysis studies of FSHD report the deregulation of genes which mediate myoblast differentiation and fusion. Transgenic mice overexpressing FRG1 recapitulate the FSHD muscular dystrophy phenotype. Our current study selectively examines how increased expression of FRG1 may contribute to myoblast differentiation defects. We generated stable C2C12 cell lines overexpressing FRG1, which exhibited a myoblast fusion defect upon differentiation. To determine if myoblast fusion defects contribute to the FRG1 mouse dystrophic phenotype, this strain was crossed with skeletal muscle specific FHL1-transgenic mice. We previously reported that FHL1 promotes myoblast fusion in vitro and FHL1-transgenic mice develop skeletal muscle hypertrophy. In the current study, FRG1 mice overexpressing FHL1 showed an improvement in the dystrophic phenotype, including a reduced spinal kyphosis, increased muscle mass and myofiber size, and decreased muscle fibrosis. FHL1 expression in FRG1 mice, did not alter satellite cell number or activation, but enhanced myoblast fusion. Primary myoblasts isolated from FRG1 mice showed a myoblast fusion defect that was rescued by FHL1 expression. Therefore, increased FRG1 expression may contribute to a muscular dystrophy phenotype resembling FSHD by impairing myoblast fusion, a defect that can be rescued by enhanced myoblast fusion via expression of FHL1.

Identification of FHL1 as a therapeutic target for Duchenne muscular dystrophy.

Utrophin is a potential therapeutic target for the fatal muscle disease, Duchenne muscular dystrophy (DMD). In adult skeletal muscle, utrophin is restricted to the neuromuscular and myotendinous junctions and can compensate for dystrophin loss in mdx mice, a mouse model of DMD, but requires sarcolemmal localization. NFATc1-mediated transcription regulates utrophin expression and the LIM protein, FHL1 which promotes muscle hypertrophy, is a transcriptional activator of NFATc1. By generating mdx/FHL1-transgenic mice, we demonstrate that FHL1 potentiates NFATc1 activation of utrophin to ameliorate the dystrophic pathology. Transgenic FHL1 expression increased sarcolemmal membrane stability, reduced muscle degeneration, decreased inflammation and conferred protection from contraction-induced injury in mdx mice. Significantly, FHL1 expression also reduced progressive muscle degeneration and fibrosis in the diaphragm of aged mdx mice. FHL1 enhanced NFATc1 activation of the utrophin promoter and increased sarcolemmal expression of utrophin in muscles of mdx mice, directing the assembly of a substitute utrophin-glycoprotein complex, and revealing a novel FHL1-NFATc1-utrophin signaling axis that can functionally compensate for dystrophin.

Four and a half LIM protein 1 gene mutations cause four distinct human myopathies: a comprehensive review of the clinical, histological and pathological features.

Mutations in the four and a half LIM protein 1 (FHL1) gene were recently identified as the cause of four distinct skeletal muscle diseases. Since the initial report outlining the first fhl1 mutation in 2008, over 25 different mutations have been identified in patients with reducing body myopathy, X-linked myopathy characterized by postural muscle atrophy, scapuloperoneal myopathy and Emery-Dreifuss muscular dystrophy. Reducing body myopathy was first described four decades ago, its underlying genetic cause was unknown until the discovery of fhl1 mutations. X-linked myopathy characterized by postural muscle atrophy is a novel disease where fhl1 mutations are the only cause. This review will profile each of the FHL1, with a comprehensive analysis of mutations, a comparison of the clinical and histopathological features and will present several hypotheses for the possible disease mechanism(s).

Juvenile polymyositis or paediatric muscular dystrophy: a detailed re-analysis of 13 cases.

AIMS: There has been much debate about the existence of juvenile polymyositis (JPM) as an entity distinct from muscular dystrophy (MD). The aim of this study was to retrospectively analyse muscle biopsies and clinical features of 13 Australian children given an initial diagnosis of JPM, to determine their clinicopathological, immunohistochemical and molecular characteristics. METHODS AND RESULTS: The muscle biopsies on 13 cases were reviewed using detailed morphological and immunoperoxidase studies, with additional protein and molecular analyses, in conjunction with clinical review. Only one case had a true connective tissue disease inflammatory myopathy. Twelve (92.3%) cases with an initial diagnosis of JPM were found on clinical, pathological and molecular review to be MD. CONCLUSIONS: Inflammatory changes in apparently sporadic juvenile myopathies should prompt consideration of an early presentation of MD. Detailed analysis of muscle histopathology, specifically the detection of subsarcolemmal blebbing, isolated fibre degeneration occurring independent of inflammatory infiltrates, patchy clustered major histocompatibility complex-I expression and a CD68+/CD3+ perimysial infiltrate, assists in the diagnosis of early MD. Specific protein and gene analysis adds support to the pathological diagnosis of dystrophy. This series adds weight to suggestions that JPM may not represent a discrete clinical or pathological entity.

SLIMMER (FHL1B/KyoT3) interacts with the proapoptotic protein Siva-1 (CD27BP) and delays skeletal myoblast apoptosis.

The fhl1 gene encoding four-and-a-half LIM protein-1 (FHL1) and its spliced isoform, SLIMMER, is mutated in reducing body myopathy, X-linked myopathy with postural muscle atrophy, scapuloperoneal myopathy, and rigid spine syndrome. In this study we have identified a novel function for SLIMMER in delaying skeletal muscle apoptosis via an interaction with the proapoptotic protein Siva-1. Siva-1 was identified as a SLIMMER-specific-interacting protein using yeast two-hybrid screening, direct-binding studies, and glutathione S-transferase pulldown analysis of murine skeletal muscle lysates. In C2C12 skeletal myoblasts, SLIMMER and Siva co-localized in the nucleus; however, both proteins exhibited redistribution to the cytoplasm following the differentiation of mononucleated myoblasts to multinucleated myotubes. In sections of mature skeletal muscle from wild type mice, SLIMMER and Siva-1 co-localized at the Z-line. SLIMMER and Siva-1 were also enriched in Pax-7-positive satellite cells, muscle stem cells that facilitate repair and regeneration. Significantly, SLIMMER delayed Siva-1-dependent apoptosis in C2C12 myoblasts. In skeletal muscle sections from the mdx mouse model of Duchenne muscular dystrophy, SLIMMER and Siva-1 co-localized in the nucleus of apoptotic myofibers. Therefore, SLIMMER may protect skeletal muscle from apoptosis.