A Germinal Center Checkpoint of AIRE in B Cells Limits Antibody Diversification.

In response to antigens, B cells undergo affinity maturation and class switching mediated by activation-induced cytidine deaminase (AID) in germinal centers (GCs) of secondary lymphoid organs, but uncontrolled AID activity can precipitate autoimmunity and cancer. The regulation of GC antibody diversification is of fundamental importance but not well understood. We found that autoimmune regulator (AIRE), the molecule essential for T cell tolerance, is expressed in GC B cells in a CD40-dependent manner, interacts with AID and negatively regulates antibody affinity maturation and class switching by inhibiting AID function. AIRE deficiency in B cells caused altered antibody repertoire, increased somatic hypermutations, elevated autoantibodies to T helper 17 effector cytokines and defective control of skin Candida albicans. These results define a GC B cell checkpoint of humoral immunity and illuminate new approaches of generating high-affinity neutralizing antibodies for immunotherapy.

Calcineurin inhibitors and renal biopsy in children with idiopathic nephrotic syndrome.

Idiopathic nephrotic syndrome (NS) is common in children, and most patients respond to corticosteroid therapy. Patients who relapse may need additional immunosuppression with cyclophosphamide, mycophenolate mofetil, calcineurin inhibitors (CNI), or rituximab. Many such patients undergo protocol renal biopsies before and after the initiation of CNI therapy. The main objective of our study was to assess the role of protocol renal biopsies in the monitoring of CNI-induced nephrotoxicity in patients with steroid-dependent (SD)/frequent relapse (FR) NS. We did an Institutional Review Board (IRB)-approved retrospective chart review of patients who were diagnosed with NS at the Children's Hospital of Michigan from January 2000 to June 2019. Study inclusion criteria were a diagnosis of NS, age 1 - 21 years at initial diagnosis, SD/FR clinical course, patients with initial steroid resistance with renal biopsy showing minimal change disease, and renal biopsy before and after CNI initiation. The data is presented on 24 patients who met study inclusion criteria. Only 3 patients (12.5%) showed evidence of chronic CNI nephrotoxicity after a median treatment 66.5 months (range 12 - 153 months). Our study revealed that a baseline renal biopsy before starting CNI therapy for children with FR/SDNS is not necessary. A renal biopsy may be considered after 2 - 3 years of CNI administration in selected few cases in whom the diagnosis of CNI nephrotoxicity might help change the management.

A Novel COL1A1-CAMTA1 Rearrangement in Cranial Fasciitis.

Cranial fasciitis is an uncommon benign fibroblastic tumor, generally histologically identical to nodular fasciitis. It develops almost exclusively in children. Cranial fasciitis manifests clinically as a painless rapidly growing solitary nodule in the head and neck area, frequently eroding the underlying bone. Thus, this entity is often confused with aggressive lesions such as sarcomas, both clinically and radiologically. Histopathologic examination is essential to differentiate between cranial fasciitis and fibrohistiocytic or even sarcomatous lesions observed in children. In this article, we present a case of cranial fasciitis with intracranial extension in a 2-year-old boy. Although USP6 rearrangement has recently been recognized as a recurring alteration in nodular fasciitis, we present a novel COL1A1-CAMTA1 fusion in this lesion.

Monozygotic twins with neuroblastoma MS have a similar molecular profile: a case of twin-to-twin metastasis.

Fetoplacental neuroblastoma metastasis has been postulated as a mechanism accounting for concordant cases where one twin develops a primary tumour and the second twin manifests the disease without an identifiable primary site. These tumours may originate and spread concomitantly due to the same genetic background shared by monozygotic twins. This study investigated the molecular profile of stage MS neuroblastoma presenting concomitantly in monozygotic twins. Comparative genomic hybridisation (aCGH) was done for each of the twin liver tumour and peripheral blood samples at diagnosis. Comparison of copy-number variation (CNV) regions revealed a set of CNVs that were common to both tumour specimens and not apparent in the blood. The CNV signature in both twins' tumours was highly similar, suggesting a common clonal origin. Additional findings included large deletion of chromosome 10 and amplification of chromosome 17. Notably, both liver samples had amplification of a short region involving DEIN (chromosome 4q34.1). Similar CNVs strongly support a common clonal origin and metastatic spread from one twin to the other. DEIN is a long-coding RNA (IncRNA) that has been found highly expressed in stage MS neuroblastoma and is likely involved in biological processes such as cell migration and metastasis.

Passage of decidual cast following poor compliance with oral contraceptive pill.

BACKGROUND: Decidual cast describes the spontaneous sloughing of endometrium as an entire piece while retaining the shape of the endometrial cavity. It may be associated with increased serum progesterone levels and must be considered as a differential diagnosis in a patient who passes tissue per vagina while on progesterone containing hormonal contraception. CASE: A 13-year-old adolescent with a history of menorrhagia since menarche, presented to the pediatric emergency room with worsening abdominal pain and heavy vaginal bleeding stopping her oral contraceptive pill 10 days prior to presentation. Her symptoms resolved spontaneously following passage of tissue per vagina which was later by histopathology to be a decidual cast. CONCLUSION: Decidual cast is a rare pathological entity that may be a side effect of progesterone-containing hormonal contraceptives, requiring patient education before use.

Complete second branchial cleft anomaly presenting as a fistula and a tonsillar cyst: an interesting congenital anomaly.

Branchial cleft anomalies make up 30% of all pediatric neck masses, but complete second branchial cleft anomalies are extremely rare. We report an unusual case of a complete second branchial cleft anomaly that presented as a draining neck fistula and a tonsillar cyst in an otherwise healthy 3-month-old girl. At the age of 7 months, the patient had been experiencing feeding difficulties, and there was increasing concern about the risk of persistent infections. At that point, the anomaly was excised in its entirety. Our suspicion that the patient had a complete second branchial cleft anomaly was confirmed by imaging, surgical excision, and histopathologic analysis.

Treatment of inflammatory myofibroblastic tumor of the subglottis with KTP laser: a case report.

Although inflammatory myofibroblastic tumors (IMTs) are seen in the lower respiratory tract in the pediatric population, few cases occurring in the larynx have been reported in the literature. Treatment of choice is complete surgical excision because of risk of recurrence. We describe a case of pediatric subglottic IMT presenting with progressive hoarseness and symptoms of persistent reactive airway treated with potassium titanyl phosphate laser. We also enumerate the number of pediatric cases of IMT that occur in the larynx and subglottis compared with those which occur in the upper respiratory tract, specifically the trachea and bronchi. To the best of our knowledge, this is the first reported case of respiratory tract IMT excision using a potassium titanyl phosphate laser and the second reported case of a pediatric laryngeal IMT showing anaplastic lymphoma kinase-1 immunoreactivity.

Conclusions and data analysis: a 6-year study of Raman spectroscopy of solid tumors at a major pediatric institute.

PURPOSE: Create a Raman spectroscopic database with potential to diagnose cancer and investigate two different diagnostic methodologies. Raman spectroscopy measures the energy of photons scattered inelastically by molecules. These molecular signatures form the basis of identifying complex biomolecules and can be used to differentiate normal from neoplastic tissue. METHODS: 1,352 spectra from 55 specimens were collected from fresh or frozen normal brain, kidney and adrenal gland and their malignancies. Spectra were obtained utilizing a Renishaw Raman microscope (RM1000) at 785 nm excitation wavelength with an exposure time of 10 to 20 s/spectrum over three accumulations. Spectra were preprocessed and discriminant function analysis was used to classify spectra based on pathological gold standard. RESULTS: The results of leave 25 % out training/testing validation were as follows: 94.3 % accuracy for training and 91.5 % for testing adrenal, 95.1 % accuracy for training and 88.9 % for testing group of brain, and 100 % accuracy for kidney training/testing groups when tissue origin was assumed. A generalized database not assuming tissue origin provided 88 % training and 85.5 % testing accuracy. CONCLUSION: A database can be made from Raman spectra to classify and grade normal from cancerous tissue. This database has the potential for real time diagnosis of fresh tissue and can potentially be applied to the operating room in vivo.

Identification of pediatric brain neoplasms using Raman spectroscopy.

PURPOSE: Raman spectroscopy can quickly and accurately diagnose tissue in near real-time. This study evaluated the capacity of Raman spectroscopy to diagnose pediatric brain tumors. EXPERIMENTAL DESIGN: Samples of untreated pediatric medulloblastoma (4 samples and 4 patients), glioma (i.e. astrocytoma, oligodendroglioma, ependymoma, ganglioglioma and other gliomas; 27 samples and 19 patients), and normal brain samples (33 samples and 5 patients) were collected fresh from the operating room or from our frozen tumor bank. Samples were divided and tested using routine pathology and Raman spectroscopy. Twelve Raman spectra were collected per sample. Support vector machine analysis was used to classify spectra using the pathology diagnosis as the gold standard. RESULTS: Normal brain (321 spectra), glioma (246 spectra) and medulloblastoma (82 spectra) were identified with 96.9, 96.7 and 93.9% accuracy, respectively, when compared with each other. High-grade ependymomas (41 spectra) were differentiated from low-grade ependymomas (25 spectra) with 100% sensitivity and 96.0% specificity. Normal brain tissue was distinguished from low-grade glioma (118 spectra) with 91.5% sensitivity and 97.8% specificity. For these analyses, the tissue-level classification was determined to be 100% accurate. CONCLUSION: These results suggest Raman spectroscopy can accurately distinguish pediatric brain neoplasms from normal brain tissue, similar tumor types from each other and high-grade from low-grade tumors.

Intraocular teratoma in association with sacrococcygeal teratoma: a clinicopathologic report.

A benign sacrococcygeal teratoma was resected from an infant at birth. Four weeks later, intraocular tumors were identified in the right eye. The eye expanded in size and was removed at 16 weeks. A benign cystic intraocular teratoma was identified.

Pseudoangiomatous stromal hyperplasia of the breast in pediatric patients: an underrecognized entity.

Pseudoangiomatous stromal hyperplasia (PASH) is a benign lesion consisting of mammary stromal proliferation with anastomosing slits mimicking vascular spaces. Grossly, it most often resembles fibroadenoma, but may commonly be confused with angiosarcoma and other types of benign vascular proliferations. While PASH has been described in female and male adults since the mid-1980s, there have been only a few accounts in the pediatric population. We present a series of 12 pediatric patients with PASH, including a 3-year-old male, who we believe to be the youngest patient to present with this entity. In our study, PASH was found in 12% of tumors diagnosed preoperatively as fibroadenomas and in 12% of cases diagnosed preoperatively as gynecomastia. Our series documents that PASH is not uncommon in pediatric breast pathology and delineates important differences between adult and pediatric presentations of this entity.

Takayasu's arteritis presenting as uveitis in a 5-year-old girl.

A 5-year-old patient presented with uveitis as initial manifestation of Takayasu's arteritis. Our patient is unique not only in the initial presentation but also in the extent of arteritis in the aortic arch and great vessels. This is only the second case reported in the literature with this unusual presentation.