Childhood-onset lupus nephritis is characterized by complex interactions between kidney stroma and infiltrating immune cells.

Children with systemic lupus erythematosus (SLE) are at increased risk of developing kidney disease, termed childhood-onset lupus nephritis (cLN). Single-cell transcriptomics of dissociated kidney tissue has advanced our understanding of LN pathogenesis, but loss of spatial resolution prevents interrogation of in situ cellular interactions. Using a technical advance in spatial transcriptomics, we generated a spatially resolved, single-cell resolution atlas of kidney tissue from eight patients with cLN and four control individuals.

The 1000 Mitoses Project: A Consensus-Based International Collaborative Study on Mitotic Figures Classification.

The identification of mitotic figures is essential for the diagnosis, grading, and classification of various different tumors. Despite its importance, there is a paucity of literature reporting the consistency in interpreting mitotic figures among pathologists. This study leverages publicly accessible datasets and social media to recruit an international group of pathologists to score an image database of more than 1000 mitotic figures collectively.

Single cell spatial transcriptomic profiling of childhood-onset lupus nephritis reveals complex interactions between kidney stroma and infiltrating immune cells.

Children with systemic lupus erythematosus (SLE) are at increased risk of developing kidney disease, termed childhood-onset lupus nephritis (cLN). Single cell transcriptomics of dissociated kidney tissue has advanced our understanding of LN pathogenesis, but loss of spatial resolution prevents interrogation of in situ cellular interactions. Using a technical advance in spatial transcriptomics, we generated a spatially resolved, single cell resolution atlas of kidney tissue (>400,000 cells) from eight cLN patients and two controls.

Use of the Seraph® 100 Microbind® Affinity Blood Filter in an adolescent patient with disseminated adenoviral disease.

Background: The Seraph® 100 Microbind® Affinity Blood Filter (Seraph® 100) is an adjunctive pathogen adsorption device with emergency use authorization for use with extracorporeal therapies to treat COVID-19 infection.

Case: Here, we describe the use of Seraph® 100 in a 17-year-old chronically immunosuppressed patient status post deceased donor kidney transplant who presented initially for hematuria, dysuria, and fevers, and was found to have disseminated adenovirus (ADV) infection complicated by nephritis, viral pneumonia, elevated transaminases, and bone marrow suppression. Despite halting immunosuppression for 2 weeks, she remained febrile to 40.

Craniolacunia and the Development of the Fetal Calvaria: An Autopsy Series With Clinical and Histological Analysis.

Background: Craniolacunia, also known as lückenschädel, is a congenital abnormality of the calvaria featuring well-circumscribed areas of marked thinning, interspersed with more-normal bone. It is most commonly associated with myelomeningocele and/or Chiari 2 malformation.

Methods: Records, photographs, and histologic sections were reviewed from 13 autopsy cases with craniolacunia.

Pediatric Low-Grade Spindle Cell Neoplasm With A Novel Fusion: A Case Report.

Objectives: Spindle cell neoplasms (SCN) share a single commonality of spindle-shaped cells on histopathology but are diverse in etiology. Expanding our collective knowledge of these neoplasms could further research in targeted therapies. We present a case of pediatric cutaneous SCN with a novel etiology, and the methods used to identify its origination.

Neonatal Skin Structure: Pressure Injury Staging Challenges.

General Purpose: To review neonatal pressure injuries (PIs), including clinical features and challenges in evaluation and staging related to the unique anatomic features of preterm neonatal skin as well as the common sites and mechanisms of injury.

Target Audience: This continuing education activity is intended for physicians, physician assistants, nurse practitioners, and nurses with an interest in skin and wound care.

Learning Objectives/outcomes: After participating in this educational activity, the participant will:1.

Thrombosis in Extracorporeal Membrane Oxygenation (ECMO) Circuits.

Thrombosis in extracorporeal membrane oxygenation (ECMO) circuits remains a frequent complication. We characterize the location, extent, structure, and clinical implications of thrombi in 53 ECMO circuits from 46 pediatric patients. The tubing, pump, and oxygenator were examined for visible thrombi.

Preterm Infant Skin Structure Is Qualitatively and Quantitatively Different From That of Term Newborns.

Background: The immature skin of preterm infants is uniquely vulnerable to pressure and chemical injury. We sought to qualitatively and quantitatively describe the histopathologic patterns of skin development in preterm infants.

Methods: Autopsy skin samples were examined for 48 liveborn preterm infants born at 18+ to 36 weeks, and control groups of term neonates and older infants/children.

Massive Post-traumatic Femoral Cyst Resulting in Pathologic Fracture in a Child: A Case Report.

Case: A 10-year-old boy experienced a pathologic diaphyseal femur fracture through a large cyst encompassing 40% of femoral length. At age 5, he had had a traumatic ipsilateral diaphyseal femur fracture, treated with flexible nailing. Biopsy at age 10 revealed a simple bone cyst with components of aneurysmal bone cyst.

Clinical and Histopathologic Predictors of Disaccharidase Deficiency in Duodenal Biopsy Specimens.

Objectives: Disaccharidase (DS) activity in duodenal biopsy specimens is the gold standard for diagnosing DS deficiency. We investigated strategies to reduce the need for DS testing and whether clinical or histopathologic factors predict DS deficiency.

Methods: A retrospective chart review analyzed 1,678 DS results in children, biopsy indication(s), and duodenal histopathology.

Necrotizing Enterocolitis in Two Siblings and an Unrelated Infant with Overlapping Chromosome 6q25 Deletions.

The pathogenesis of necrotizing enterocolitis (NEC) remains poorly understood but is thought to be multifactorial. There are no specific recurring chromosomal abnormalities previously associated with NEC. We report 3 cases of intestinal necrosis associated with large chromosome 6 deletions.

Ceftriaxone-induced drug reaction mimicking acute splenic sequestration crisis in a child with hemoglobin SC disease.

Background: Acute splenic sequestration crisis is a complication of sickle cell disease (SCD) occurring when intrasplenic red blood cell (RBC) sickling prevents blood from leaving the spleen, causing acute splenic enlargement. Although typically seen in young children, it has been reported in older children with hemoglobin (Hb)SC disease, eventually resulting in functional asplenia. Ceftriaxone is a frequently used antibiotic of choice for children with SCD, because of its efficacy against invasive pneumococcal disease.

Pathologist Effort in the Performance of Fetal, Perinatal, and Pediatric Autopsies: A Survey of Practice.

Context: -Autopsy is an important tool for quality assurance and improving patient care. Fetal, perinatal, and pediatric autopsies have the additional benefit of identifying conditions that may have increased risk of recurrence. In contrast to adult autopsies, special collections and testing are frequently used.

Minimally Invasive Adenocarcinoma of the Lung as Second Malignant Neoplasm Following Pediatric Rhabdomyosarcoma.

Primary pulmonary tumors are extremely rare in the pediatric population; however, sporadic cases of invasive pulmonary adenocarcinoma as a second malignant neoplasm (SMN) have been described in survivors of pediatric cancers. Pediatric patients with rhabdomyosarcoma (RMS) have a particularly increased risk of developing a SMN when compared to the general population, though pulmonary adenocarcinoma has not been previously described in a RMS patient. A 12-year-old female previously treated for stage IV pelvic RMS was found to have a left pulmonary nodule on surveillance computed tomography.

Iatrogenic injury and unexpected hospital death in the newborn.

Neonates are unusually vulnerable to iatrogenic injury due to small body size, delicate tissues, and immature immune systems. Investigation of an unexpected neonatal death in the hospital should begin with a review of the medical record and discussion with medical staff involved in the patient׳s care. Postmortem investigation should include a complete and well-documented autopsy.

Unexpected coronary artery findings in mucopolysaccharidosis. Report of four cases and literature review.

Introduction: The mucopolysaccharidosis syndromes are a group of lethal inherited disorders affecting multiple organ systems by the progressive deposition of glycosaminoglycan. Advances in treatment such as enzyme replacement and hematopoietic stem cell transplantation have significantly improved the outcome of these disorders. An in-depth understanding of the pathophysiology of heart disease in these disorders is essential since death from cardiac causes continues to be common.

Asymptomatic DNAemia heralds CMV-associated NEC: case report, review, and rationale for preemption.

Human cytomegalovirus (CMV) infection may be acquired in very low birth weight and extremely low birth weight (ELBW) infants from breast milk. The clinical relevance of such infections is uncertain. There is no consensus on whether screening breast milk for CMV, freezing/pasteurizing milk before feeding, or performing virological monitoring on at-risk infants is warranted.

Sustained remission of severe Multicentric Castleman disease following multiagent chemotherapy and tocilizumab maintenance.

Castleman disease is a rare lymphoproliferative disorder, which presents in a unicentric or multicentric fashion. Multicentric Castleman disease (MCD) is associated with significant systemic symptoms, in part related to the underlying role of interleukin-6 in disease pathogenesis. Treatment for MCD has not been well established and prognosis has historically been poor.

Perigestational dietary folic acid deficiency protects against medulloblastoma formation in a mouse model of nevoid basal cell carcinoma syndrome.

Hereditary nevoid basal cell carcinoma syndrome (NBCCS) is caused by PTCH1 gene mutations that result in diverse neoplasms including medulloblastoma (MB). Epidemiological studies report reduced pediatric brain tumor risks associated with maternal intake of prenatal vitamins containing folic acid (FA) and FA supplements specifically. We hypothesized that low maternal FA intake during the perigestational period would increase MB incidence in a transgenic NBCCS mouse model, which carries an autosomal dominant mutation in the Ptch1 gene.

Long-term use of ventricular assist device as a bridge to recovery in acute fulminant myocarditis.

We report the successful long-term use of a left ventricular assist device (Berlin EXCOR) as a bridge to recovery in a patient with fulminant parvovirus B19 myocarditis. The use of this device allowed time for myocardial recovery, avoiding the need for cardiac transplantation.

Familial LCAT deficiency in a child with nephrotic syndrome.

Background: Lecitin cholesterol acyltransferase (LCAT) deficiency comprises a group of rare disorders related to HDL metabolism. These disorders are characterized by ophthalmologic, hematologic, and renal findings. Case diagnosis/treatment: A 15-year-old female who presented with nephrotic syndrome and hypertension was diagnosed with LCAT deficiency by renal biopsy and LCAT enzyme activity.

Successful management of factor IX inhibitor-associated nephrotic syndrome in a hemophilia B patient.

Background: Nephrotic syndrome (NS) is a recognized complication of immune tolerance induction (ITI) therapy, a treatment strategy used to treat inhibitors in patients with hemophilia B receiving factor IX concentrate.

Case Diagnosis/treatment: We present a 4-year-old boy with hemophilia B and an inhibitor who underwent ITI, and developed NS 19 months into this therapy. A percutaneous renal biopsy was safely performed with factor IX (FIX) concentrate administration both preceding and following the procedure.

Unusual presentations of BK virus infections in pediatric renal transplant recipients.

BKV has emerged as a significant pathogen in the field of transplantation, predominantly causing BKV nephropathy in renal transplant recipients and hemorrhagic cystitis in HSCT recipients. However, case reports describe more diverse complications, and we too present three unusual cases of BKV infections in pediatric renal transplant recipients. First, we describe a case of biopsy-proven renal damage secondary to BKV prior to the onset of viremia, demonstrating that BKV nephropathy can occur without preceding viremia.