Oncostatin-M Does Not Predict Treatment Response in Inflammatory Bowel Disease in a Pediatric Cohort.

OBJECTIVES: This study aimed to determine whether mRNA expression of oncostatin-M (OSM) and its receptor (OSMR) in initial, pre-treatment intestinal biopsies is predictive of response to tumor necrosis factor antagonists (anti-TNF) in a pediatric inflammatory bowel disease (IBD) cohort. Secondary outcomes correlated OSM and OSMR expression with demographic variables; IBD type, extent, phenotype, and severity; laboratory values; and endoscopic findings. METHODS: A retrospective chart review was conducted on 98 pediatric patients. Patients' clinical courses were stratified as follows: failed anti-TNF (n = 14), quiescent on anti-TNF (n = 36), anti-TNF naïve (n = 19), and age-matched non-IBD controls (n = 29). The mRNA from each patient's pre-treatment ileal or colonic biopsy was isolated, and expression of OSM and OSMR was analyzed. RESULTS: There was no difference in OSM or OSMR expression among the three IBD groups; however, expression was significantly higher in patients with IBD than non-IBD controls (P < 0.001). OSM and OSMR were more highly expressed in patients with ulcerative colitis (UC) with a Mayo score of 3 (P = 0.0092 and P = 0.0313, respectively). High OSM expression correlated with severe disease activity indices at diagnosis (P = 0.002), anemia at diagnosis (P = 0.0236), and need for immunomodulators (P = 0.0193) and steroids (P = 0.0273) during patients' clinical courses. CONCLUSIONS: OSM and OSMR expression were not predictive of response to anti-TNF in our pediatric cohort. OSM expression did correlate with IBD compared with healthy controls as well as with several clinical indicators of severe IBD.

Successful use of transarterial radioembolization with yttrium-90 (TARE-Y90) in two children with hepatoblastoma.

Primary malignant liver tumors are rare but all require surgical resection as part of therapy with curative intent. A minority of patients have resectable tumors at diagnosis. Chemotherapy has a therapeutic role in hepatoblastoma but only one-third of patients have resectable disease at diagnosis. Two children with hepatoblastoma and suboptimal responses to initial chemotherapy received therapy with transarterial radioembolization utilizing yttrium-90 (TARE-Y90) and had significant response leading to resection and remission. The role of TARE-Y90 needs to be studied further to define its use in primary pediatric liver neoplasms.

Post-transplant lymphoproliferative disease of the larynx.

Laryngeal post-transplant lymphoproliferative disease (PTLD) is rare. Here, we describe two pediatric cases. The first, a 15-month-old who underwent liver transplantation at 5 weeks, presented with airway distress. Airway evaluation identified epiglottic and arytenoid infiltrate, and biopsy was consistent with polymorphic PTLD. The second, a 23-month-old who underwent liver transplantation at 13 months, presented with progressive stridor. Airway evaluation revealed sub-mucosal infiltrate of the epiglottis, arytenoids, post-cricoid region, and uvula. Biopsy was consistent with monomorphic PTLD. Airway findings and symptoms resolved for both after immunosuppression reduction. PTLD diagnosis requires a high index of suspicion in post-transplant patients with airway obstruction.

Association between Testicular Microlithiasis and Testicular Neoplasia: Large Multicenter Study in a Pediatric Population.

Purpose To retrospectively define the strength of association between testicular microlithiasis and testicular neoplasia in a large geographically diverse pediatric population. Materials and Methods Retrospective review of scrotal ultrasonographic (US) examination reports and pathology specimens obtained between January 2000 and May 2014 at six academic pediatric hospitals in North America was performed. Reported cases were reviewed to confirm microlithiasis. Radiology and pathology data bases were searched for pathology-proven testicular tumors (benign or malignant germ cell or stromal tumors). Association strength (risk) was expressed in terms of odds ratios (ORs) with and without adjustment for fixed study site effects based on logistic regression. Results A total of 37 863 individuals underwent scrotal US during the study period. Mean age was 11.1 years ± 4.7 [standard deviation] in boys with microlithiasis and 9.1 years ± 5.9 in boys without microlithiasis (P < .001). Microlithiasis was confirmed in 2.90% of patients (1097 of 37 863; range, 1.61%-5.25% across sites). It was unilateral in 21.97% (241 of 1097) of patients and bilateral in 78.0% (856 of 1097). Tumor was identified in 4.64% (51 of 1097) of boys with microlithiasis and 0.33% (122 of 36 766) of boys without (unadjusted OR, 14.65; 95% confidence interval [CI]: 10.29, 20.84; adjusted OR, 14.19). Malignant germ cell tumors were identified in 2.8% (31 of 1097) of boys with microlithiasis and 0.12% (45 of 36 766) of boys without microlithiasis (unadjusted OR, 17.26; 95% CI: 11.8, 25.25; adjusted OR, 22.37). Sex cord-stromal tumors were identified in 0.46% (five of 1097) of boys with microlithiasis and 0.079% (29 of 36 766) of boys without (unadjusted OR, 5.8; 95% CI: 2.1, 16; adjusted OR, 6.39). Conclusion There is a strong association between testicular microlithiasis and primary testicular neoplasia in this pediatric population. © RSNA, 2017.

Behcet Disease Initially Presenting as Deep Venous Thrombosis: A Case Report.

Behcet disease is a potentially life-threatening multisystemic vasculitis with thrombotic tendency. Mucocutaneous ulcers, arthritis, and uveitis are the most recognizable features, but may be absent at the time of medical evaluation. We report a case in which a 8-year old patient presented with spontaneous bilateral lower extremity deep venous thromboses, and screening for rheumatologic symptoms led to diagnosing Behcet. This case demonstrates that deep venous thromboses can be the initial event bringing a patient with Behcet to medical attention, highlighting the importance of screening for underlying rheumatologic diseases in pediatric patients who present with unprovoked thrombosis.

Autophagy mediates epithelial cytoprotection in eosinophilic oesophagitis.

OBJECTIVE: The influence of eosinophilic oesophagitis (EoE)-associated inflammation upon oesophageal epithelial biology remains poorly understood. We investigated the functional role of autophagy in oesophageal epithelial cells (keratinocytes) exposed to the inflammatory EoE milieu. DESIGN: Functional consequences of genetic or pharmacological autophagy inhibition were assessed in endoscopic oesophageal biopsies, human oesophageal keratinocytes, single cell-derived ex vivo murine oesophageal organoids as well as a murine model recapitulating EoE-like inflammation and basal cell hyperplasia. Gene expression, morphological and functional characterisation of autophagy and oxidative stress were performed by transmission electron microscopy, immunostaining, immunoblotting, live cell imaging and flow cytometry. RESULTS: EoE-relevant inflammatory conditions promoted autophagy and basal cell hyperplasia in three independent murine EoE models and oesophageal organoids. Inhibition of autophagic flux via chloroquine treatment augmented basal cell hyperplasia in these model systems. Oesophageal keratinocytes stimulated with EoE-relevant cytokines, including tumour necrosis factor-α and interleukin-13 exhibited activation of autophagic flux in a reactive oxygen species-dependent manner. Autophagy inhibition via chloroquine treatment or depletion of Beclin-1 or ATG-7, augmented oxidative stress induced by EoE-relevant stimuli in murine EoE, oesophageal organoids and human oesophageal keratinocytes. Oesophageal epithelia of paediatric EoE patients with active inflammation displayed increased autophagic vesicle content compared with normal and EoE remission subjects. Functional flow cytometric analysis revealed autophagic flux in human oesophageal biopsies. CONCLUSIONS: Our findings reveal for the first time that autophagy may function as a cytoprotective mechanism to maintain epithelial redox balance and homeostasis under EoE inflammation-associated stress, providing mechanistic insights into the role of autophagy in EoE pathogenesis.

LNK/SH2B3 regulates IL-7 receptor signaling in normal and malignant B-progenitors.

Philadelphia chromosome-like acute lymphoblastic leukemia (Ph-like ALL) is a high-risk ALL commonly associated with alterations that affect the tyrosine kinase pathway, tumor suppressors, and lymphoid transcription factors. Loss-of-function mutations in the gene-encoding adaptor protein LNK (also known as SH2B3) are found in Ph-like ALLs; however, it is not clear how LNK regulates normal B cell development or promotes leukemogenesis. Here, we have shown that combined loss of Lnk and tumor suppressors Tp53 or Ink4a/Arf in mice triggers a highly aggressive and transplantable precursor B-ALL. Tp53-/-Lnk-/- B-ALLs displayed similar gene expression profiles to human Ph-like B-ALLs, supporting use of this model for preclinical and molecular studies. Preleukemic Tp53-/-Lnk-/- pro-B progenitors were hypersensitive to IL-7, exhibited marked self-renewal in vitro and in vivo, and were able to initiate B-ALL in transplant recipients. Mechanistically, we demonstrated that LNK regulates pro-B progenitor homeostasis by attenuating IL-7-stimuated JAK/STAT5 signaling via a direct interaction with phosphorylated JAK3. Moreover, JAK inhibitors were effective in prolonging survival of mice transplanted with Lnk-/-Tp53-/- leukemia. Additionally, synergistic administration of PI3K/mTOR and JAK inhibitors further abrogated leukemia development. Hence, our results suggest that LNK suppresses IL-7R/JAK/STAT signaling to restrict pro-/pre-B progenitor expansion and leukemia development, providing a pathogenic mechanism and a potential therapeutic approach for B-ALLs with LNK mutations.

Histologic patterns of thymic involvement in Langerhans cell proliferations: a clinicopathologic study and review of the literature.

Thymic involvement by Langerhans cell histiocytosis (LCH) has been described mainly in isolated case reports. A description of the histopathologic patterns of LCH proliferations in the thymus, together with therapeutic implications, has not, to our knowledge, been previously addressed. The pathology consultation files at Children's Hospital of Pittsburgh of the University of Pennsylvania Medical Center were reviewed for cases of thymic involvement by LCH. Relevant cases in the literature were also reviewed, and the histopathology and clinical course of those cases were collected. Nine consultation cases of thymic involvement were reviewed, together with 23 cases in the literature, which provided adequate pathologic description and ancillary confirmation (n  =  32), revealing 4 distinct pathologic groups. Group 1 showed microscopic collection of hyperplastic LCH-like cells in incidental thymectomies of patients without LCH disease, requiring no further treatment (n  =  7; 22%). Group 2 showed solitary and/or cystic LCH of the thymus with gland disruption, and at least 3 cases resolved without systemic therapy (n  =  10; 31%). Group 3 showed more variable thymic involvement in multisystemic LCH disease, with either a medullary restricted pattern or more diffuse gland involvement, requiring adjuvant therapy and having a higher mortality rate (n  =  13; 41%). Group 4 showed a mixed histiocytic lesion with a concurrent LCH and juvenile xanthogranuloma-like proliferation (n  =  2; 6%). Thymic involvement in LCH is quite rare. Based on our cases and those in the literature, we propose 4 distinct pathologic groups of thymic involvement in Langerhans cell proliferations with relevance for diagnosis and treatment.

Malignant rhabdoid tumor of the bladder and ganglioglioma in a 14 year-old male with a germline 22q11.2 deletion.

Malignant rhabdoid tumors (MRTs) are rare pediatric malignancies characterized by clinically aggressive lesions that typically show loss of SMARCB1 expression. We herein describe a case of a malignant rhabdoid tumor of the bladder in a 14-year-old male with an autism spectrum disorder and a de novo 3 Mb germline deletion in chromosome band 22q11.2 that included the SMARCB1 gene. The malignancy developed in the setting of chronic hematuria (>2 years) following the occurrence of two other lesions: a central nervous system ganglioglioma and an intraoral dermoid cyst. MRTs of the bladder are exceedingly rare, and this patient is the oldest child reported with this tumor to date. This case adds to the growing body of literature regarding the recently described, phenotypically diverse, distal 22q11.2 syndrome. Furthermore, this is the first reported case in which an MRT of the bladder appears to have developed from a pre-existing bladder lesion. Finally, this case further supports a rhabdoid tumorigenesis model in which heterozygous loss of SMARCB1 predisposes to initial tumor formation with intact SMARCB1 expression, with subsequent inactivation of the other SMARCB1 allele, which results in transformation into more malignant lesions.

Intra-articular nodular fasciitis of the knee in a pediatric patient.

The differential diagnosis for an intra-articular lesion in the knee of a pediatric patient is broad. Diagnostic considerations include pigmented villonodular synovitis (PVNS)-the most common intra-articular tumor-and a variety of both benign and malignant tumors, including lipomas, hemangiopericytomas, nodular fasciitis, parosteal osteosarcomas, and fibromyxoid sarcomas. If there is concern over possible malignant lesions, a tumor surgeon should be consulted. Precise pathologic diagnosis is ideal for identifying these enigmatic lesions and for determining the appropriate treatment plan. This article presents the case of a 13-year-old boy who presented with 1-month duration of knee pain and no history of trauma to the extremity. Physical examination revealed pain along the medial and lateral joint lines, pain with range of motion, and limited range of motion of the affected knee. Magnetic resonance imaging revealed a 3×1×3-cm lesion in the posterolateral corner that was believed to be localized PVNS. Arthroscopically, there was no evidence of PVNS, but a posterolateral soft tissue mass was found and removed, which was pathologically diagnosed as a rare, benign, intra-articular nodular fasciitis. When working with intra-articular masses, it is important to assess the likelihood of malignancy and to both consult a tumor surgeon and use the appropriate surgical tumor principles when malignancy is a concern. Additionally, the pathology team should be consulted prior to surgery and be on standby during arthroscopic evaluation of the knee to help with precise diagnosis of the intra-articular mass. Discussing the case with the pathologist with imaging studies present is helpful and often aids in the diagnosis of the lesion.

Lipofibromatosis: an institutional and literature review of an uncommon entity.

We report six new cases of lipofibromatosis, an uncommon pediatric soft tissue neoplasm. This is the only series of patients to be described since the initial case series of 45 patients that characterized this entity in 2000. The purpose of this study was to characterize the presentation of lipofibromatosis to further define the clinical phenotype of this rare entity. Six patients were diagnosed with lipofibromatosis at our institution from 2000 to 2012. Patient age, sex, and ethnicity were recorded, along with tumor site and size, management, and recurrence data. Half of our patients were younger than 2 years old at presentation and the other half were school age. Boys and girls were affected with equal frequency. In five of six patients, lipofibromatosis presented in its "classic" form as a mass on the distal extremities. These tumors typically measured 1 to 2 cm in diameter, in contrast to case reports in the medical literature highlighting the occurrence of lipofibromatosis of greater size and at varied anatomic sites. The tumors in our series were managed using excision, with recurrence noted in 33%. Lipofibromatosis is an uncommon tumor typically found on the distal extremities of infants, although it can appear in various sizes and locations. It should be considered in the differential diagnosis of pediatric soft tissue neoplasms.

DICER1 mutations in childhood cystic nephroma and its relationship to DICER1-renal sarcoma.

The pathogenesis of cystic nephroma of the kidney has interested pathologists for over 50 years. Emerging from its initial designation as a type of unilateral multilocular cyst, cystic nephroma has been considered as either a developmental abnormality or a neoplasm or both. Many have viewed cystic nephroma as the benign end of the pathologic spectrum with cystic partially differentiated nephroblastoma and Wilms tumor, whereas others have considered it a mixed epithelial and stromal tumor. We hypothesize that cystic nephroma, like the pleuropulmonary blastoma in the lung, represents a spectrum of abnormal renal organogenesis with risk for malignant transformation. Here we studied DICER1 mutations in a cohort of 20 cystic nephromas and 6 cystic partially differentiated nephroblastomas, selected independently of a familial association with pleuropulmonary blastoma and describe four cases of sarcoma arising in cystic nephroma, which have a similarity to the solid areas of type II or III pleuropulmonary blastoma. The genetic analyses presented here confirm that DICER1 mutations are the major genetic event in the development of cystic nephroma. Further, cystic nephroma and pleuropulmonary blastoma have similar DICER1 loss of function and 'hotspot' missense mutation rates, which involve specific amino acids in the RNase IIIb domain. We propose an alternative pathway with the genetic pathogenesis of cystic nephroma and DICER1-renal sarcoma paralleling that of type I to type II/III malignant progression of pleuropulmonary blastoma.

Thymic stromal lymphopoietin-elicited basophil responses promote eosinophilic esophagitis.

Eosinophilic esophagitis (EoE) is a food allergy-associated inflammatory disease characterized by esophageal eosinophilia. Current management strategies for EoE are nonspecific, and thus there is a need to identify specific immunological pathways that could be targeted to treat this disease. EoE is associated with polymorphisms in the gene that encodes thymic stromal lymphopoietin (TSLP), a cytokine that promotes allergic inflammation, but how TSLP might contribute to EoE disease pathogenesis has been unclear. Here, we describe a new mouse model of EoE-like disease that developed independently of IgE, but was dependent on TSLP and basophils, as targeting TSLP or basophils during the sensitization phase limited disease. Notably, therapeutic TSLP neutralization or basophil depletion also ameliorated established EoE-like disease. In human subjects with EoE, we observed elevated TSLP expression and exaggerated basophil responses in esophageal biopsies, and a gain-of-function TSLP polymorphism was associated with increased basophil responses in patients with EoE. Together, these data suggest that the TSLP-basophil axis contributes to the pathogenesis of EoE and could be therapeutically targeted to treat this disease.

Congenital mydriasis associated with megacystis microcolon intestinal hypoperistalsis syndrome.

We report a case of congenital mydriasis in a neonate with megacystis microcolon intestinal hypoperistalsis syndrome (MMIHS). Pilocarpine testing and gastrointestinal pathology in our patient suggest that the mydriasis is due to an underlying smooth muscle myopathy of the iris sphincter muscle. These findings may have important implications regarding the pathogenesis of MMIHS.

Low back pain in a child associated with acute onset cauda equina syndrome: a rare presentation of an aggressive vertebral hemangioma: a case report.

BACKGROUND: Back pain prevalence in the pediatric age group is less compared with adults. There is a wide range of possible etiologies, and tumors such as primary spinal hemangiomas are uncommon. Most are incidental findings and asymptomatic; however, painful lesions can be presented in up to 0.9% to 1.2% of cases. These lesions can produce neurologic involvement either spinal cord compression or cauda equina syndrome as in our case. The aim of this study is to describe a case of low back pain in a child due to a vertebral hemangioma complicated with acute cauda equina syndrome, and performed a literature review that will help us to recognize this aggressive variance making an early treatment feasible. METHODS: A 13-year-old female, follow-up in an outer health care center due to a L1 vertebral hemangioma, characterized by 3 years of low back pain without neurologic symptoms presented to our emergency department with an acute cauda equina syndrome. RESULTS: An outside magnetic resonance imaging showed complete obliteration of the spinal canal at the level of the conus medullaris related to retropulsion of bone at L1. She underwent 2-stage surgical treatment: complete posterior L1 laminectomy and partial T12-L2 laminectomies, with partial L1 vertebrectomy and posterior fusion with instrumention from T11 to L3. Three weeks later, embolization before anterior fusion with inner body cage was performed. Forty months after surgery, she is doing well with no neurologic deficits. CONCLUSIONS: Even though hemangiomas are not a common cause of back pain, they should be taken into account. It is important to recognize the aggressive variance so an early treatment could be performed. There is no enough clinical data to establish guidelines of management in children, therefore, the treatment should be individualized.

Imaging of pediatric ovarian neoplasms.

We review the clinical and imaging characteristics of the most common ovarian neoplasms in children and adolescents. Because of the widespread use of diagnostic imaging, incidental ovarian neoplasms might be encountered during the evaluation of abdominal pain, trauma or other indications and might pose a diagnostic dilemma. Conducting adequate imaging studies under these conditions is important, as management strategies differ according to the size and appearance of the lesion as well as the age of the patient. US dominates in gynecological imaging because of its excellent visualization, absence of ionizing radiation and sedation risks and comparatively low cost. For further examination of indeterminate lesions found using US, MRI is being used more progressively in this field, particularly for the evaluation of complex pelvic masses with the aim of distinguishing benign and malignant conditions and conditions requiring surgical intervention. CT is reserved primarily for tumor staging and follow-up and for emergency situations.

Leclercia adecarboxylata cellulitis in a child with acute lymphoblastic leukemia.

Leclercia adecarboxylata is a rare, gram-negative rod that has been infrequently reported in the literature. The organism has been documented to cause solitary infections in immunocompromised hosts and polymicrobial wound infections in the immunocompetent. We present a case of an 8-year-old boy with significant past medical history of acute lymphoblastic leukemia who developed cellulitis due to local infection by L. adecarboxylata. This case is presented to raise awareness of this rare organism's ability to cause common cutaneous disease, especially in the immunocompromised.