Nephrotic Syndrome in a Child With NPHS2 Mutation.

Steroid resistant nephrotic syndrome (SRNS) accounts for 30% of all cases of nephrotic syndrome (NS) in children and frequently leads to end stage kidney disease (ESKD). About 30% of children with SRNS demonstrate causative mutations in podocyte- associated genes. Early identification of genetic forms of SRNS is critical to avoid potentially harmful immunosuppressive therapy. A 2-year-old male patient with NS and no family history of renal disease did not respond to 4-week steroid treatment. Kidney biopsy demonstrated mesangial proliferative glomerulopathy with basement membrane dysmorphism. Tacrolimus and Lisinopril were added to therapy pending results of genetic testing. Kidney Gene panel showed a NPHS2 c.413G>A (p.Arg138Gln) homozygous pathogenic variant. This missense variant is considered a common pathogenic founder mutation in European populations. A diagnosis of autosomal-recessive form of nonsyndromic SRNS due to NPHS2 causative variant was made. Immunosuppresive therapy was stopped, Lizinopril dose was increased and weekly infusions of Albumin/furosemide were initiated to manage edema. This case demonstrates that early genetic testing in children with SRNS avoids prolonged potentially harmful immunosuppressive therapy, allows for timely genetic family counseling, and allows earlier consideration for future living related donor kidney transplantation.

Cell Free Microbial DNA Utilization at a Children's Hospital.

Background: We investigated the utilization of cell free microbial DNA (cfDNA) at a Children's Hospital. Materials and Methods: cfDNA results were assessed regarding the contribution to therapeutic decisions. Results: Of 80 tests on 59 children, 1 test was unevaluable. At least one agent was identified in 45/79 (57%) tests from 34/59 (58.2%) children, 34/79 (43.0%) were negative in 31/59(52.5%) children. Of 45 positive results, 24/79 (30%) were contributory, 15/79 (19%) were diagnostic, 6/79 (7.6%) were diagnostic but diagnosis could have been made with other testing modalities, and 3/79 (3.8%) were diagnostic with minimal previous workup. 21/79 (26.6%) positives were noncontributory. Of 35 negative results, 9/79 (11.4%) were contributory, 26/79 (33.0%) were noncontributory. Efficiency was 30.4-41.8%. cfDNA detected agents not detected by conventional techniques in 22/79 (27.8%), detected different agents in 9/79 (11.4%), and failed to detect agents identified by conventional techniques in 4 (5%). Conclusions: Efficiency of cfDNA was 30.4-41.8.

Fibrocartilaginous Dysplasia of the Proximal Femur in Two Pediatric Patients, Including a Pathologic Fracture in a Patient With McCune-Albright Syndrome.

Fibrocartilaginous dysplasia (FCD) is a variant of fibrous dysplasia that often involves the proximal femur in young adults. It has a similar appearance on imaging as other entities but has stippled calcifications within the lesion. The differential diagnosis often includes benign and malignant tumors such as fibrous dysplasia, chondroblastoma, enchondroma, and chondrosarcoma. Histology is required for diagnosis and treatment is typically surgical due to the potential for pain, pathologic fracture, and deformity. We report the clinical presentation, imaging findings, and management of two pediatric patients with fibrocartilaginous dysplasia of the proximal femur to (1) highlight that recognition that fibrous dysplasia may contain cartilage upon frozen section will avoid overly aggressive therapy, and (2) FCD can occur in the McCune-Albright syndrome.

Novel Autopsy Findings in Premature Infant With Beckwith-Wiedemann Syndrome Uniparental Disomy: Multifocal Developmental Dysplastic Chrondromatous Lesions and Cortical Neuronal Heterotopias.

BACKGROUND: Beckwith-Wiedemann syndrome (BWS) is an overgrowth disorder that exhibits etiologic genomic imprinting characterized by molecular heterogeneity and phenotypic variability. Associations with localized developmental dysplastic chondromatous lesions and cortical neuronal heterotopias have not previously been described. CASE PRESENTATION: A 33-week gestational age female had an omphalocele and intractable hypoglycemia at birth. The placenta demonstrated placental mesenchymal dysplasia. Detection of hypermethylation of IC1 and hypomethylation of IC2 confirmed Beckwith-Wiedemann syndrome, most likely due to uniparental disomy. Additional findings included right mid-tibial and right 5-8th developmental dysplastic chondromatous lesions, absent corpus callosum and numerous right-sided cortical neuronal heterotopias, right hemihypertrophy, multiple cystic hepatic mesenchymal hamartomas and hepatic infantile hemangiomas, nisidioblastosis and cystic pancreatic lesions. The infant died with multi-organ failure and anasarca at 7 weeks of life. CONCLUSION: Beckwith-Wiedemann syndrome anomalies may include multifocal developmental dysplastic chondromatous lesions and cerebral neuronal heterotopias, lateralized, and corpus callosum aplasia.

Primary Intraosseous Granular Cell Tumor of the Sphenoid and Central Skull Base in a Pediatric Patient.

BACKGROUND: Granular cell tumors occur in all ages and many anatomic sites. In the craniofacial region, they typically arise in soft tissue, not bone. We present a primary intra-osseous granular cell tumor of the sphenoid and central skull base arising in a 12- year- old girl. CASE REPORT: A 12-year-old female with sickle cell disease and Jeavons syndrome presented with seizures. Imaging and partial resection revealed an expansile benign granular cell tumor (GCT) involving the sphenoid body, pterygoid process, and central skull base. The disease has remained stable after 36-month follow up. DISCUSSION: GCT primarily involving the osseous sphenoid/skull base has not been previously reported in a child. Although mostly benign, some are aggressive, with malignant transformation in 1-2%. Surgery is the mainstay of treatment, but in the skull base this may be limited by adjacent critical structures. Decision-making is guided by anatomic extent, histology, and clinical behavior.

Current Utilization of Electron Microscopy in the Pediatric Pathology Setting: A Survey by the SPP Practice Committee.

BACKGROUND: Electron microscopy (EM), once an important component in diagnosing pediatric diseases, has experienced a decline in its use. To assess the impact of this, pediatric pathology practices were surveyed regarding EM services. METHODS: The Society of Pediatric Pathology Practice Committee surveyed 113 society members from 74 hospitals. Settings included 36 academic tertiary, 32 free-standing children's, and 6 community hospitals. RESULTS: Over 60% maintained in-house EM services and had more than 2 pathologists interpreting EM while reporting a shortage of EM technologists. Freestanding children's hospitals had the most specimens (100-200 per year) and more diverse specimen types. Hospitals with fewer than 50 yearly specimens often used reference laboratories. Seventeen had terminated all in-house EM services. Challenges included decreasing caseloads due to alternative diagnostic methods, high operating costs, and shortages of EM technologists and EM-proficient pathologists. Kidney, liver, cilia, heart, and muscle biopsies most often required EM. Lung/bronchoalveolar lavage, tumor, skin, gastrointestinal, nerve, platelet, and autopsy samples less commonly needed EM. CONCLUSIONS: The survey revealed challenges in maintaining EM services but demonstrated its sustained value in pediatric pathology. Pediatric pathologists may need to address the centralization of services and training to preserve EM diagnostic proficiency among pathologists who perform ultrastructural interpretations.

Pathologist Pediatric In-Patient Genetic Stewardship.

Background: Costs for sendout genetic testing on in-patients are billed to the hospital. Turnaround times are several weeks, often extending past the inpatient hospitalization.Materials and Methods: We concurrently reviewed all sendout genetic in-patient test requests over an 18-month period, deferring those that could be obtained as an outpatient, directing the tests to less expensive laboratories with complementary testing profiles, and identifying no-charge sponsored tests.Results: Of 121 test requests, 25 were deferred, alternative less expensive laboratories were identified for 8, 16 requests were directed to sponsored tests, for a 42.3% cost saving. Of the 96 tests sent, 18 (18.8%) identified an explanatory genetic abnormality.Conclusions: Approximately 40% of the sendout genetic testing costs were reduced with prior test review. Deferment, alternative laboratories, and sponsored tests contributed to cost savings. Efficiency of diagnostic inpatient genetic testing was approximately 20%.

WAGR, Sex Reversal, Bilateral Gonadoblastomas, and Intralobar Nephrogenic Rests: Uncertainties of Pre-Biopsy Chemotherapy in a High Risk Syndrome for Nephroblastoma.

Background: WT1 deletions are associated with nephroblastomas, WT mutations are associated with 46, XY sex reversal. It is unclear why only a few WT1 deletions are associated with sex reversal. Case report. This 46, XY female had a 15.2 MB interstitial deletion of 11p14.1p11.2, which included WT1 and FSHB. No pathogenic abnormalities were identified in 156 other genes associated with disorders of sexual development. Bilateral gonadoblastomas were incidentally diagnosed at 17 months of age at the time of prophylactic gonadectomies. She was treated without biopsy for bilateral nephroblastomas radiologically identified at 18 months of age. Bilateral partial nephrectomies contained treated intralobular nephrogenic rests. Conclusion: It is unclear why WT1 deletions are less associated with 46, XY sex reversal than WT1 mutations. Treating suspected nephroblastomas without biopsy, even in patients with syndromes associated with bilateral nephroblastomas, may still lead to diagnostic and therapeutic uncertainties.

Avoiding Spurious Low Platelet Counts by Redrawing Specimens with First Time Low Platelet Counts.

INTRODUCTION: We reviewed our policy of redrawing our pediatric patients with first time platelet counts <100 K/ml to assess the frequency of correction. MATERIALS AND METHODS: In a Children's Hospital 25-month review of patients that underwent automatic redraws due to low first time platelet counts, we determined the frequency of corrected counts and the sites where these original low platelet counts originated. Only the repeat draw results were reported. RESULTS: Of 99 children with redrawn specimens, 62% of platelet counts corrected. The most frequent corrections occurred in specimens from the emergency department (74%), pediatric intensive care (71%), and operating room (67%), the fewest from the cardiac intensive care (38%) and general hospital floors (44%). CONCLUSIONS: The policy of redrawing patients with first time platelet counts <100 K resulted in correction in 62%, and avoided delays and additional charges for repeat testing ordered by the provider.

De novo collapsing glomerulopathy in a pediatric kidney transplant recipient with COVID-19 infection.

The negative impact of COVID-19 on adults with underlying chronic kidney disease, including kidney transplant recipients, has been well documented. Children have a less severe presentation and better prognosis compared to adults. However, little is known regarding the spectrum of COVID-19 infection in children and adolescents with underlying autoimmune disorders necessitating solid organ transplant and long-term immunosuppressive therapy. Case Report. An adolescent male developed end-stage kidney disease secondary to microscopic polyangiitis requiring a living-donor kidney transplant. Six years later, he developed antibody-mediated rejection of his kidney transplant. During his rejection treatment course, he contracted SARS-CoV-2 and developed new-onset nephrotic syndrome with severe acute kidney injury. Kidney transplant biopsy revealed de novo collapsing focal segmental glomerulosclerosis on a background of chronic active antibody mediated rejection. Immunostaining for SARS-CoV-2 on the biopsy specimen demonstrated positive staining of the proximal tubular epithelium consistent with intra-renal viral infection. Pulse corticosteroids, intravenous immunoglobulin, and temporary reduction of anti-metabolite therapy resulted in successful recovery with return of graft function back to pre-infection baseline. This case highlights the clinical conundrum of treating kidney transplant recipients with active rejection in the midst of the COVID-19 pandemic. Pediatric kidney transplant recipients can develop severe COVID-19-related kidney complications. Judicious immunosuppression modulation is necessary to balance infection and rejection risk.

Correction to: An adolescent male with acute kidney injury: questions.

The authors regret that the name of the author Randall Craver was incorrectly rendered as "Randall Carver." The original article has been corrected.

Correction to: An adolescent male with acute kidney injury: answers.

The authors regret that the name of the author Randall Craver was incorrectly rendered as "Randall Carver." The original article has been corrected.

Fatal Eosinophilic Myocarditis in a Healthy 17-Year-Old Male with Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2c).

Background: Cardiac damage is frequently referred to in patients with SARS-CoV-2, is usually diagnosed by enzyme elevations, and is generally thought to be due to underlying coronary artery disease. There are references to cardiomyopathies accompanying coronavirus, but there has been no histologic confirmation.Case report: A previously healthy 17 year male old presented in full cardiac arrest to the emergency department after a 2 day history of headache, dizziness, nausea and vomiting. Autopsy demonstrated an enlarged flabby heart with eosinophilic myocarditis. There was no interstitial pneumonia or diffuse alveolar damage. Postmortem nasopharyngeal swabs detected severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) known to cause coronavirus disease 2019 (COVID-19). No other cause for the eosinophilic myocarditis was elucidated.Conclusion: Like other viruses, SARS-CoV-2 may be associated with fulminant myocarditis.

Early identification of transplant glomerulopathy in pediatric kidney transplant biopsies: A single-center experience with electron microscopy analysis.

Banff 2013 criteria recommend performing ultrastructural studies with electron microscopy (EM) in kidney transplant biopsies if the technology is available. We sought to determine the impact of EM on enhancing diagnostic findings in pediatric kidney transplant biopsies and the prognostic information gained from the additional findings. All kidney transplant biopsies since routine EM use started on June 1, 2014, until October 31, 2016, were reviewed. Primary outcome measures included the positive yield frequency of EM use defined as an upgraded diagnosis based on EM findings relative to light microscopy, and 12-month kidney allograft outcome of progression to ESRD or doubling of serum creatinine stratified by transplant glomerulopathy (TG) status on EM. Eighty unique kidney transplant biopsies were reviewed. EM studies were completed for 61 biopsies (76%). Complication rate was low (3.7%). In 61 biopsies where EM was completed, EM findings included foot process fusion (62%), endothelial cell swelling (38%), subendothelial lucencies (31%), and glomerular basement membrane duplication (41%). EM confirmed FSGS recurrence in three cases. In the remaining 58 cases, there was a positive yield of 31% where 18 biopsies were upgraded to a worse category after TG identification on EM. Kidney allograft outcome was poor regardless whether TG was detected early on EM or advanced on LM. Routine EM use in analyzing pediatric kidney transplant biopsies proved safe and provided valuable additional diagnostic information in almost one-third of cases. Additional studies are needed to determine if clinical interventions for early TG identified on EM can improve long-term outcomes.

Pediatric Tracheal Rhabdomyosarcoma Masquerading as a Granuloma.

We describe a posterior wall intratracheal embryonal rhabdomyosarcoma (RMS) arising in a 6-year-old tracheostomized child masquerading as reactive granulation tissue and review all reported cases of pediatric intratracheal RMS. The child underwent laser debulking of the tumor and postoperative radiation and chemotherapy with no evidence of recurrence at 2-year follow-up. A literature review revealed four previous cases of pediatric primary tracheal or intratracheal RMS, and remission was achieved in all but one case with surgery, chemotherapy, and radiation. Pathologic evaluation of tracheal mucosal granulation tissue may merit consideration, particularly in patients with increased risk factors.

Multifocal Rounded Intraplacental Hematomas, Placental Abruption and Intrauterine Fetal Demise.

BACKGROUND: Rounded intraplacental hematomas (RIH) have a distinct rounded hemorrhagic appearance located within the placental parenchyma. Hemorrhagic villous infarctions (infarcts that when sectioned have hemorrhagic centers) are probably older RIH. RIH have been associated with acute abruptions. CASE REPORT: We describe multiple RIHs and hemorrhagic villous infarctions in various stages of development that arose between 20 and 27 weeks gestation, demonstrated by ultrasound, that developed an acute abruption and fetal death. CONCLUSIONS: The findings of RIHs, hemorrhagic infarcts, and lesions in between support the evolution of hemorrhagic villous infarctions from RIHs. These lesions can arise in the second trimester, and can be detected by ultrasound. These multiple lesions in various stages of evolution suggest an ongoing rather than a discrete insult.

Intratracheal Keloid.

BACKGROUND: Keloidal scarring can complicate surgical procedures. CASE REPORT: This 21-month-old African-American child developed a keloid around his tracheostomy that extended into the trachea. CONCLUSION: Keloidal formation from a tracheostomy site can extend into the trachea.

Renal Tubular Mitochondrial Abnormalities in Complex II/III Respiratory Chain Deficiency.

Defects in the respiratory chain may present with a wide spectrum of clinical signs and symptoms. In this "Images in Pathology" discussion we correlate the clinical, histologic, and ultrastructural findings in a 12-year-old male with a complex II/III respiratory chain deficiency and kidney dysfunction.