Expanding Our Knowledge of Molecular Pathogenesis in Histiocytoses: Solitary Soft Tissue Histiocytomas in Children With a Novel CLTC::SYK Fusion.

The histiocytoses comprise a histopathologically and clinically diverse group of disorders bearing recurrent genomic alterations, commonly involving the BRAF gene and mitogen-activated protein kinase pathway. In the current study, a novel CLTC :: SYK fusion in 3 cases of a histopathologically distinct histiocytic neoplasm arising as solitary soft tissue lesions in children identified by next-generation sequencing and fluorescence in situ hybridization is described. Morphologically, all 3 neoplasms were composed of sheets of cells with round-oval nuclei and vacuolated eosinophilic cytoplasm but, in contrast to classic juvenile xanthogranuloma (JXG), Touton giant cells were absent.

Secretory-IgA binding to intestinal microbiota attenuates inflammatory reactions as the intestinal barrier of preterm infants matures.

Previous work has shown that Secretory-IgA (SIgA) binding to the intestinal microbiota is variable and may regulate host inflammatory bowel responses. Nevertheless, the impact of the SIgA functional binding to the microbiota remains largely unknown in preterm infants whose immature epithelial barriers make them particularly susceptible to inflammation. Here, we investigated SIgA binding to intestinal microbiota isolated from stools of preterm infants <33 weeks gestation with various levels of intestinal permeability.

Sentinel bowel loop as a marker for primary segmental intestinal volvulus in extreme low birth weight neonates.

Primary segmental intestinal volvulus is a rare condition that may affect neonates. This condition occurs when a loop of bowel torses around the axis of its mesentery without any other abnormality or malrotation. In the earlier stages, the diagnosis can be challenging due to the lack of specific clinical and radiographic signs.

Diagnostic limitations and considerations in the imaging evaluation of advanced multicentric infantile myofibromatosis.

Infantile myofibromatosis, the most common fibrous tumor of infancy, is classified in 2 forms; as a solitary nodule or as numerous, widely-distributed multicentric lesions with or without visceral involvement. Although benign, multicentric myofibromas are still associated with a high incidence of morbidity and mortality due to the infiltration of critical structures. Herein, we present a case of an infant with aggressive and mutation-negative myofibromas distributed throughout the vascular, respiratory, and gastrointestinal systems.

Atypical smooth muscle tumor of the vagina--a pediatric case report and review of the literature.

Vaginal tumors in children are uncommon. This report describes the rare case of an atypical smooth muscle tumor arising from the vagina in a pediatric patient managed with tumor resection, vaginal reconstruction, and continent urinary diversion. We also discuss a review of the literature and a brief report detailing our experience with pediatric vaginal tumors.

The MHC class I-related FcRn ameliorates murine Lyme arthritis.

The identification of the neonatal FcR (FcRn) as an IgG homeostasis regulator has led to research aimed at delineating a role for FcRn in humorally mediated disease. FcRn is a class I-related molecule that prolongs the half-life of serum IgG by preferentially binding IgG at low pH and inhibiting its degradation. Its role in protective immunity to infectious organisms is unknown.

Host-adapted Borrelia burgdorferi in mice expresses OspA during inflammation.

Antibody responses to outer surface protein A (OspA) of Borrelia burgdorferi may occur during periods of arthritis late in the clinical course of untreated Lyme disease. These antibody responses are paradoxical, given the conclusive evidence demonstrating that B. burgdorferi transmitted to the mammalian host expresses little or no OspA.