Novel STAT3 variant causing infantile-onset autoimmune disease.

Signal transducer and activator of transcription 3 (STAT3) is a member of the STAT protein family implicated in the development of infantile-onset multisystem autoimmune disease. STAT3-related autoimmune disease is characterized by multiorgan autoimmunity, lymphoproliferative disease, and recurrent infections. The presentation is variable, with some patients also developing neonatal diabetes mellitus and interstitial lung disease. Gain-of-function variants in the Src homology 2 domain, leading to autophosphorylation and activation of STAT3, have been previously reported in patients with disease. Here, we report a patient with a novel missense variant, p.Glu616Ala, in STAT3 presenting with infantile-onset multisystem autoimmune disease.

Whole-Exome Sequencing Identifies a Novel POLG Frameshift Variant in an Adult Patient Presenting with Progressive External Ophthalmoplegia and Mitochondrial DNA Depletion.

Mitochondrial DNA (mtDNA) depletion syndromes are a group of autosomal recessive disorders associated with a spectrum of clinical diseases, which include progressive external ophthalmoplegia (PEO). They are caused by variants in nuclear DNA (nDNA) encoded genes, and the gene that encodes for mtDNA polymerase gamma (POLG) is commonly involved. A splice-site mutation in POLG, c.3104+3A > T, was previously identified in three families with findings of PEO, and studies demonstrated this variant to result in skipping of exon 19. Here, we report a 57-year-old female who presented with ophthalmoplegia, ptosis, muscle weakness, and exercise intolerance with a subsequent muscle biopsy demonstrating mitochondrial myopathy on histopathologic evaluation and multiple mtDNA deletions by southern blot analysis. Whole-exome sequencing identified the previously characterized c. 3104+3A > T splice-site mutation in compound heterozygosity with a novel frameshift variant, p.Gly23Serfs ∗ 236 (c.67_88del). mtDNA copy number analysis performed on the patient's muscle showed mtDNA depletion, as expected in a patient with biallelic pathogenic mutations in POLG. This is the first reported case with POLG p.Gly23Serfs ∗ 236, discovered in a patient presenting with features of PEO.

Composite Neuroblastoma Metastatic to a Lymph Node: The Novel Histopathologic Diagnosis of a Unique Multiclonal Neoplasm.

OBJECTIVE: Composite neuroblastoma is a tumor composed of multiple tumoral clones within the neuroblastoma family. To date, establishing this unique histopathologic diagnosis has required the evaluation of the primary tumor mass. We report a case of composite neuroblastoma diagnosed by evaluation of a metastatic lymph node. METHODS: One abdominal lymph node involved by tumor was evaluated in a 6-year-old boy. The primary abdominal mass was not examined. Following histopathologic examination, clonality studies using comparative genomic hybridization (CGH) and fluorescence in situ hybridization (FISH) were also performed. RESULTS: Two distinct tumor components were identified by histopathologic evaluation and classified as differentiating neuroblastoma (component A) and poorly differentiated neuroblastoma (component B). Based on the patient's age, each clone was further classified as Unfavorable Histology. The presence of these two different tumoral clones was confirmed by CGH and FISH. CONCLUSION: This case affirms the histopathologic approach to evaluating composite tumors, as established by the International Neuroblastoma Pathology Classification (INPC) model for ganglioneuroblastoma, nodular tumors. Also, when both components are metastatic, this case demonstrates that composite tumors can be diagnosed by the evaluation of metastatic lesions alone. Finally, it supports the addition of composite neuroblastoma to a future version of the INPC.

Sclerosing Epithelioid Fibrosarcoma of the Kidney: First Reported Case in a Young Child.

Sclerosing epithelioid fibrosarcoma (SEF) is a rare variant of fibrosarcoma primarily arising in the deep soft tissue of the extremities and trunk. Despite having the morphologic appearance of a low-grade sarcoma, it generally has an aggressive clinical course with frequent local recurrences and distant metastases. It typically occurs in middle aged adults and is characterized by immunoexpression of MUC4 and recurrent gene fusions, most commonly EWSR1-CREB3L1. We report a primary renal SEF in a 4-year-old male. To our knowledge, this is the youngest patient reported with SEF and the second case of SEF in a pre-adolescent child. It is the eleventh reported case of primary renal SEF in the literature. While SEF arising in visceral organs is rare, the kidney is the most common primary site of any visceral organ. This case demonstrates SEF can occur in pre-adolescents, is an important consideration when evaluating sarcomas in young children, and should be considered in the differential diagnosis for primary renal tumors.

An unusual presentation of primary pulmonary extranodal marginal zone lymphoma of mucosal associated lymphoid tissue: An autopsy case report.

A 40 year old female with no documented medical history presented to the Emergency Department with several days of lethargy and altered mental status. She was found to be anemic, thrombocytopenic, and hypotensive. The patient was found to be in severe metabolic acidosis, became bradycardic, and quickly deteriorated. Clinicians suspected thrombotic thrombocytopenic purpura, and the diagnosis was supported by ADAMTS13 testing. The clinicians attempted to place a Quinton catheter for emergent plasmapheresis, but the patient expired before definitive treatment could be initiated. Autopsy was obtained and revealed a right middle lobe consolidation grossly consistent with lymphoid tissue or tumor.

A novel case of lymphangiomatosis in HIV.

Diffuse lymphangiomatosis is a rare disorder characterized by abnormal proliferation of lymphatic channels. It can involve just one organ or multiple organs, such as liver, spleen, lungs, and bone. This disorder generally presents in children and young adults, but in rare cases, patients first present with symptoms in adulthood. Here, we describe a 48-year-old HIV-positive man who presented with shortness of breath. Computed tomography scan revealed a large right-sided pleural effusion and a heterogeneously enhancing liver. Thoracentesis demonstrated a chylous effusion and subsequent liver biopsy revealed a proliferation of dilated lymphatics to establish a diagnosis of lymphangiomatosis.

Molecular interactions in the retinal basement membrane system: a proteomic approach.

Basement membranes (BMs) are physiologically insoluble extracellular matrix sheets present in all multicellular organisms. They play an important role in providing mechanical strength to tissues and regulating cell behavior. Proteomic analysis of BM proteins is challenged by their high molecular weights and extensive post-translational modifications. Here, we describe the direct analysis of an in vivo BM system using a mass spectrometry (MS) based proteomics approach. Retinal BMs were isolated from embryonic chick eyes. The BM macromolecules were deglycosylated and separated by low percentage gradient SDS PAGE, in-gel digested and analyzed by LC-MS/MS. This identified over 27 extracellular matrix proteins in the retinal BM. A semi-quantitative measure of protein abundance distinguished, nidogens-1 and -2, laminin subunits α1, α5, ß2, and γ1, agrin, collagen XVIII, perlecan, FRAS1 and FREM2 as the most abundant BM protein components. Laminin subunits α3, ß1, γ2, γ3 and collagen IV subunits α5 and α6 were minor constituents. To examine binding interactions that contribute to the stability of the retinal BM, we applied the LC-MS/MS based approach to detect potential BM complexes from the vitreous. Affinity-captured nidogen- and heparin-binding proteins from the vitreous contained >10 and >200 proteins respectively. Comparison of these protein lists with the retinal BM proteome reveals that glycosaminoglycan and nidogen binding interactions play a central role in the internal structure and formation of the retinal BM. In addition, we studied the biomechanical qualities of the retinal BM before and after deglycosylation using atomic force microscopy. These results show that the glycosaminoglycan side chains of the proteoglycans play a dominant role in regulating the thickness and elasticity of the BMs by binding water to the extracellular matrix. To our knowledge, this is the first large-scale investigation of an in vivo BM system using MS-based proteomics.