Thrombosis of the Renal Vein and Inferior Vena Cava Associated With Placental Fetal Vascular Malperfusion in a Neonate Exposed to Methadone Maintenance Therapy In Utero.

Methadone, an opioid agonist, is the recommended treatment for pregnant women with opioid use disorder (OUD). Fetal/neonatal autopsy findings as well as placental changes in the setting of maternal OUD or methadone maintenance therapy (MMT) are not well-characterized. Here we present a case of a neonate who had exposure to MMT while in utero and died shortly after birth and was subsequently found to have multifocal calcified renal vein thrombosis, a recent inferior vena cava thrombus, and placental features of fetal vascular malperfusion at autopsy.

Cystic Crypt Changes in Midgestational Human Vermiform Appendix: An Unrecognized Transient Histologic Feature.

INTRODUCTION: Lewis and Huff briefly described the presence of "microcystic cryptitis" in some of fetal vermiform appendices (VA) at autopsy. We further characterized these crypt changes (CC), their timing of occurrence, and tested their association with infection/inflammatory conditions. METHODS: Hematoxylin and eosin-stained slides of 345 VA were evaluated for the presence or absence of CC and their different morphologies. Autopsy reports were reviewed for evidence of amniotic fluid or fetal systemic infection and placental inflammatory conditions. RESULTS: Crypt dilatation with or without irregularity of the lumen, crypt dilatation with semiattenuated epithelium, intraluminal apoptotic debris and inflammatory cells, especially eosinophils, and foci of swirled spindled cells with calcifications or multinucleated giant cells were observed, either alone or in combination, in at least 58.5% (202/345) of the VA. CC began to appear at 17 weeks, peaked at 20 to 25 weeks (with up to 82% of VA exhibiting CC during this time), and followed by a steady decline beyond 28 weeks gestation. χ2 test of independence showed no significant association (P = .435; >0.05) between the presence and absence of CC and infection status of the fetus or placenta. CONCLUSION: The underrecognized CC of the developing fetal vermiform appendix (VA) showed distinct temporal pattern of occurrence and did not seem to be affected by the presence or absence of infection, which so far favored their being a part of the normal gut developmental process.

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.

Relevance of C5b9 immunostaining in the diagnosis of neonatal hemochromatosis.

BACKGROUND: Neonatal hemochromatosis caused by a gestational alloimmune mechanism or gestational alloimmune liver disease (GALD) is a rare perinatal disorder characterized by intra- and extrahepatic iron overload. It is believed to result from complement-mediated liver injury, in which the classical complement pathway is activated by maternal antibody/fetal antigen complexes, leading to hepatocyte lysis by the membrane attack complex C5b9. According to some authors, C5b9 expression in more than 75% of liver parenchyma is specific for GALD. METHODS: We conducted a retrospective multicentric immunohistochemical study with anti-C5b9 in GALD cases (n = 25) and non-GALD cases with iron overload (n = 36) and without iron overload (n = 18). RESULTS: C5b9 was expressed in 100% of GALD cases but involved more than 75% of the liver parenchyma in only 26% of the cases. C5b9 was detected in 26.75% of the non-GALD cases with more than 75% of positive parenchyma in maternal erythrocytic alloimmunization, herpes and enterovirus hepatitis, bile acid synthetic defect, DGUOK mutation, Gaucher disease, cystic fibrosis, and giant-cell hepatitis with autoimmune hemolytic anemia. CONCLUSION: Diagnosis and therapeutic management of GALD cannot only be based on C5b9 expression in liver samples as it is not specific of this disease.

Ultrasound and MRI predictors of surgical bowel resection in pediatric Crohn disease.

BACKGROUND: Imaging predictors for surgery in children with Crohn disease are lacking. OBJECTIVE: To identify imaging features of the terminal ileum on short-interval bowel ultrasound (US) and MR enterography (MRE) in children with Crohn disease requiring surgical bowel resection and those managed by medical therapy alone. MATERIALS AND METHODS: This retrospective study evaluated patients 18 years and younger with Crohn disease undergoing short-interval bowel US and MRE (within 2 months of one another), as well as subsequent ileocecectomy or endoscopy within 3 months of imaging. Appearance of the terminal ileum on both modalities was compared between surgical patients and those managed with medical therapy, with the following parameters assessed: bowel wall thickness, mural stratification, vascularity, fibrofatty proliferation, abscess, fistula and stricture on bowel US; bowel wall thickness, T2 ratio, enhancement pattern, mesenteric edema, fibrofatty proliferation, abscess, fistula and stricture on MRE. A two-sided t-test was used to compare means, a Mann-Whitney U analysis was used for non-parametric parameter scores, and a chi-square or two-sided Fisher exact test compared categorical variables. Imaging findings in surgical patients were correlated with location-matched histopathological scores of inflammation and fibrosis using a scoring system adapted from the Simple Endoscopic Score for Crohn Disease, and a Spearman rank correlation coefficient was used to compare inflammation and fibrosis on histopathology. RESULTS: Twenty-two surgical patients (mean age: 16.5 years; male/female: 13/9) and 20 nonsurgical patients (mean age: 14.8; M/F: 8/12) were included in the final analysis. On US, the surgical group demonstrated significantly increased mean bowel wall thickness (6.1 mm vs. 4.7 mm for the nonsurgical group; P = 0.01), loss of mural stratification (odds ratio [OR] = 6.3; 95% confidence interval [CI]: 1.4-28.4; P = 0.02) and increased fibrofatty proliferation (P = 0.04). On MRE, the surgical group showed increased mean bowel wall thickness (9.1 mm vs. 7.2 mm for the nonsurgical group; P = 0.02), increased mean T2 ratio (4.6 vs. 3.6 for the nonsurgical group; P = 0.03), different enhancement patterns (P = 0.03), increased mesenteric edema (P = 0.001) and increased stricture formation (OR = 8.2; 95% CI: 1.8-36.4; P = 0.005). Nineteen of 22 ileocecectomy specimens showed severe inflammation and 21/22 showed severe fibrosis, with significant correlation between inflammation and fibrosis scores (ρ = 0.55; P = 0.008); however, correlation with imaging findings was limited by the uniformity of findings on histopathology. CONCLUSION: Children with terminal ileal Crohn disease requiring surgical bowel resection demonstrate more severe manifestations of imaging features traditionally associated with both active inflammation and chronic fibrosis than those managed medically on US and MRE, findings that are corroborated by histopathology. These features may potentially serve as imaging biomarkers indicating the necessity for surgical intervention.

Peptide spectra in Wilms tumor that associate with adverse outcomes.

BACKGROUND: The 2013 Children's Oncology Group (COG) blueprint for renal tumor research challenges investigators to develop new, risk-specific biological therapies for unfavorable histology and higher-risk Wilms tumor (WT) in an effort to close a persistent survival gap and to reduce treatment toxicities. As an initial response to this call from the COG, we used imaging mass spectrometry to determine peptide profiles of WT associated with adverse outcomes. MATERIALS AND METHODS: We created a WT tissue microarray containing 2-mm punches of formalin-fixed, paraffin-embedded specimens archived from 48 sequentially treated WT patients at our institutions. Imaging mass spectrometry was performed to compare peptide spectra between three patient groups as follows: unfavorable versus favorable histology, treatment success versus failure, and COG higher- versus lower-risk disease. Statistically significant peptide peaks differentiating groups were identified and incorporated into a predictive model using a genetic algorithm. RESULTS: One hundred thirty-one peptide peaks were differentially expressed in unfavorable versus favorable histology WT (P < 0.05). Two hundred three peaks differentiated treatment failure from success (P < 0.05). Seventy-one peaks differentiated COG higher-risk disease from the very-low, low, and standard-risk groups (P < 0.05). These peaks were used to develop predictive models that could differentiate among patient groups 98.49%, 94.46%, and 98.55% of the time, respectively. Spectral patterns were internally cross-validated using a leave-20% out model. CONCLUSIONS: Peptide spectra can discriminate adverse behavior of WT. After future external validation and refinement, these models could be used to predict WT behavior and to stratify intensity of chemotherapy regimens. Furthermore, peptides discovered in the model could be sequenced to identify potential risk-specific drug targets.

Esophageal epithelial and mesenchymal cross-talk leads to features of epithelial to mesenchymal transition in vitro.

BACKGROUND: Esophageal fibrosis is a complication of eosinophilic esophagitis (EoE) which has been attributed to both subepithelial fibrosis and to epithelial to mesenchymal transition (EMT), a process by which epithelial cells acquire mesenchymal features. Common to both causes of EoE-fibrosis is the notion that granulocyte-derived TGF-ß, induces myofibroblast differentiation of the target cell. To date, the role of esophageal epithelial cells as effector cells in esophageal fibrosis has never been explored. Herein, we investigated consequences of cross-talk between esophageal epithelial cells and fibroblasts, and identified profibrotic cytokines which influence the development of EMT in vitro. METHODS AND RESULTS: Stimulation of primary fetal esophageal fibroblasts (FEF3) with conditioned media (CEM) from esophageal epithelial cells (EPC2-hTERT), primed FEF3 cells to secrete IL-1ß and TNFα, but not TGFß. To determine whether these cytokines signaled in a paracrine fashion to esophageal epithelial cells, FEF3 cells were stimulated with CEM, followed by transfer of this fibroblast conditioned media (FCM) to EPC2-hTERT cells. Epithelial FCM stimulation increased expression of mesenchymal markers and reduced E-cadherin expression, features of EMT which were TNFα and IL-1ß-dependent. Using organotypic culture models, primary EoE epithelial cells exhibited features of EMT compared to non-EoE cells, corresponding to patterns of EMT in native biopsies. CONCLUSIONS: Esophageal epithelial cell and fibroblast cross-talk contributes to esophageal fibrosis. Our results suggest that features of EMT can develop independent of TGF-ß and granulocytes, which may have important implications in treatment of EoE.

Eosinophilic esophagitis: updated consensus recommendations for children and adults.

Eosinophilic esophagitis (EoE) is a clinicopathologic condition of increasing recognition and prevalence. In 2007, a consensus recommendation provided clinical and histopathologic guidance for the diagnosis and treatment of EoE; however, only a minority of physicians use the 2007 guidelines, which require fulfillment of both histologic and clinical features. Since 2007, the number of EoE publications has doubled, providing new disease insight. Accordingly, a panel of 33 physicians with expertise in pediatric and adult allergy/immunology, gastroenterology, and pathology conducted a systematic review of the EoE literature (since September 2006) using electronic databases. Based on the literature review and expertise of the panel, information and recommendations were provided in each of the following areas of EoE: diagnostics, genetics, allergy testing, therapeutics, and disease complications. Because accumulating animal and human data have provided evidence that EoE appears to be an antigen-driven immunologic process that involves multiple pathogenic pathways, a new conceptual definition is proposed highlighting that EoE represents a chronic, immune/antigen-mediated disease characterized clinically by symptoms related to esophageal dysfunction and histologically by eosinophil-predominant inflammation. The diagnostic guidelines continue to define EoE as an isolated chronic disorder of the esophagus diagnosed by the need of both clinical and pathologic features. Patients commonly have high rates of concurrent allergic diatheses, especially food sensitization, compared with the general population. Proved therapeutic options include chronic dietary elimination, topical corticosteroids, and esophageal dilation. Important additions since 2007 include genetic underpinnings that implicate EoE susceptibility caused by polymorphisms in the thymic stromal lymphopoietin protein gene and the description of a new potential disease phenotype, proton pump inhibitor-responsive esophageal eosinophila. Further advances and controversies regarding diagnostic methods, surrogate disease markers, allergy testing, and treatment approaches are discussed.

Mosaic trisomy 17: variable clinical and cytogenetic presentation.

Mosaic trisomy 17 is rare with only 28 cases reported and the clinical presentation is highly variable. The diagnosis is most commonly made by prenatal karyotype and in most cases is followed by a normal postnatal karyotype on blood lymphocytes.We present two cases of mosaic trisomy 17 diagnosed prenatally,with follow up in multiple tissues at birth. In the first case,trisomy 17 was identified in all amniocytes, and at birth standard results of chromosome analysis in peripheral blood were normal,but mosaic trisomy 17 was identified (50­75%) in skin fibroblasts by genome-wide SNP array analysis. This patient presented with congenital heart disease, asymmetry, intestinal malrotation, and other anomalies and died on day 9 of life. In the second patient amniocentesis after ultrasound finding of tetralogy of Fallot showed mosaic trisomy 17. Postnatally, results of a SNP array were normal in blood, buccal mucosa, and skin. It is possible that the cardiac defect is related to trisomy 17 in key tissues during heart development, although at birth the aneuploidy could not be identified in tissues that are routinely analyzed for diagnosis. These cases add to our understanding of mosaic trisomy 17, highlighting the failure to diagnose this aneuploidy in peripheral blood.

Changing indications for upper endoscopy in children during a 20-year period.

OBJECTIVES: In parallel with the increase in pediatric esophagogastroduodenoscopy (EGD) procedures since the 1970s, the incidence of disorders that require EGD for diagnosis in children has increased. The aim of this study was to identify changes in subject characteristics and endoscopic procedures during a 20-year interval in children undergoing EGD at a single center. PATIENTS AND METHODS: All of the children undergoing first EGD with biopsy in 1985, 1995, or 2005 were identified. Details of the clinical presentation and EGD were abstracted from medical records in a random sample of subjects within each time point. RESULTS: The number of first-time EGDs rose dramatically from 107 in 1985 to 1294 in 2005. The proportion of subjects that were younger than 1 year of age varied significantly from 13% in 1985 to 23% in 1995 and 8% in 2005 (P < 0.001). The proportion of subjects with gastrointestinal (GI) bleeding declined from 34% to 5% during the 20-year interval (P < 0.001), whereas the proportion with abdominal pain increased from 23% to 43% (P < 0.01). During the same interval, the proportion of subjects with complete EGD (biopsies from the esophagus, stomach, and duodenum) increased from 18% of EGDs in 1985 to 95% in 2005 (P < 0.001). CONCLUSIONS: This study of children undergoing first-time EGDs with biopsy during a 20-year interval demonstrated significant differences in subject characteristics and endoscopy practices. The inclusion of children with less severe clinical presentation and the collection of greater numbers of biopsies per procedure may contribute to the rising incidence rates of pediatric GI disorders.

Isolation and characterization of a novel Francisella sp. from human cerebrospinal fluid and blood.

We describe the isolation of a Francisella sp. from normally sterile sites in acutely ill patients in two different states within 2 years. Microbiologic and molecular analyses indicate that this organism represents a novel Francisella sp. Clinicians and microbiologists should be aware of this new potential pathogen, as infection may be more common than recognized.

Intracytoplasmic sperm injection (ICSI) with transmission of a ring(Y) chromosome and ovotesticular disorder of sex development in offspring.

We present a newborn infant with ovotesticular disorder of sex development and sex chromosome mosaicism with a supernumerary ring(Y), and a normal female cell line (47,XXr(Y)[10]/46,XX[40]. The ring (Y) was inherited from the child's father, and was transmitted following assisted reproductive technology and intracytoplasmic sperm injection (ICSI). The father presented with infertility and oligospermia, but cytogenetic analysis had not been carried out as part of the infertility workup. The Y containing cell line had not been seen on amniocentesis, which had shown a 46,XX apparently normal female karyotype in all cells studied. Molecular analysis using polymorphic probes from the X chromosome demonstrated that the 47,XXr(Y) cell line in the child was consistent with inheritance from the father, following meiosis I paternal non-disjunction. This report underscores the need to obtain chromosome analysis in couples with infertility who undergo assisted reproduction.

Histological features of ileitis differentiating pediatric Crohn disease from ulcerative colitis with backwash ileitis.

BACKGROUND/AIM: Pediatric ileocolonic Crohn disease (CD) may be difficult to distinguish from ulcerative colitis (UC) with backwash ileitis (BWI). The primary aim of the study was to determine the probability of CD in children with a confluent colitis and ileitis when newly diagnosed with inflammatory bowel disease (IBD). METHODS: A retrospective observational study of 100 newly diagnosed patients with IBD was performed. Two pathologists reviewed ileal biopsy specimens for 8 histological features. Biopsy and clinical features were evaluated for predictive ability of a final diagnosis of CD. RESULTS: The presence of crypt distortion, lamina propria (LP) expansion, and acute LP inflammation combined with 4 clinical variables in multivariate regression analysis had adequate discriminative validity when comparing the mean probability of a final CD diagnosis between CD and not-CD groups (0.90 vs. 0.59, p value <0.001). When crypt distortion, LP expansion, and acute LP inflammation are present in any combination, the sensitivity and specificity for presence of CD ranges 38.4-57% and 92.9-100%, respectively. CONCLUSIONS: Combining histological features of ileitis and clinical variables can adequately discriminate between the presence and absence of Crohn disease in children who present with confluent colitis and ileitis. Combined presence of certain histological features has high specificity for CD.

Diagnosis and localization of focal congenital hyperinsulinism by 18F-fluorodopa PET scan.

OBJECTIVES: To assess the accuracy of 18F-fluoro-L-dihydroxyphenylalanine ([18F]-DOPA) PET scans to diagnose focal versus diffuse disease and to localize focal lesions in infants with congenital hyperinsulinism. STUDY DESIGN: Twenty-four infants with hyperinsulinism unresponsive to medical therapy were studied. Patients were injected intravenously with [18F]-DOPA, and PET scans were obtained for 1 hour. Images were coregistered with abdominal CT scans. RESULTS: The diagnosis of focal or diffuse hyperinsulinism was correct in 23 of the 24 cases (96%) and equivocal in 1 case. [18F]-DOPA PET identified focal areas of high uptake of radiopharmaceutical in 11 patients. Pathology results confirmed that all 11 had focal adenomatosis, and the locations of these lesions matched the areas of increased [18F]-DOPA uptake on the PET scans in all of the cases. CONCLUSIONS: [18F]-DOPA PET scans were 96% accurate in diagnosing focal or diffuse disease and 100% accurate in localizing the focal lesion. These results suggest that [18F]-DOPA PET imaging should be considered in all infants with congenital hyperinsulinism who need to have pancreatectomy.

Pulmonary arteriole muscularization in lambs with diaphragmatic hernia after combined tracheal occlusion/glucocorticoid therapy.

OBJECTIVE: A morphometric study was performed to examine the effects of prenatal glucocorticoids, which were administered 48 hours before birth, on muscularization of small pulmonary arterioles (<60 microm diameter) in lambs with diaphragmatic hernia (DH) after fetal tracheal occlusion (TO). STUDY DESIGN: DH was created in 23 fetal sheep at 65 days gestation. TO was performed in 16 of 24 fetuses between 110 and 140 days of gestation; 9 of the fetuses were exposed prenatally to betamethasone (0.5 mg/kg body weight) 48 hours before delivery. Six sham-operated animals served as controls. Sections of paraffin that were embedded in lung tissues were stained with Elastin-Van Gieson, and the percentage of medial wall thickness (MWT) was determined. RESULTS: The percentage of MWT in DH lambs (29.6% +/- 1.9%) was increased compared with sham animals (18.1% +/- 1.3%) and was not different from that of DH/TO animals (30.3% +/- 1.7%). In DH/TO + glucocorticoid lambs, the percentage of MWT (24.6% +/- 1.2%) was significantly lower than in the DH/TO group but was higher than the sham group. CONCLUSION: In fetuses who underwent prolonged TO therapy for severe DH, prenatal glucocorticoid treatment decreased medial hypertrophy of pulmonary arterioles by approximately 19%. We speculate that such structural changes may have contributed to improve gas exchange that was observed in this model.

Fetal pulmonary malformations: defining histopathology.

Although classification schemes have sought to categorize congenital cystic lung malformations, studies including the pathology of pulmonary malformations occurring specifically during the fetal period are limited. To better characterize such histopathology, we reviewed a total of 23 fetal lung malformations seen at the Children's Hospital of Philadelphia from 1996 to 2004. Twenty-one of the 23 fetal pulmonary malformations could be categorized into 1 of 3 groups based upon the predominant histologic features present within each lesion. Group 1 (9/21) demonstrated tubular airspaces lined by columnar epithelium. Group 2 (6/21) contained airspaces lined by cuboidal epithelium and surrounded by smooth muscle with abundant interstitial mesenchyme. Group 3 (6/21) showed a mixture of relatively mature-appearing airspaces lined by flattened epithelium and scattered dilated bronchiole-like structures. Cysts were of variable size but in all cases showed a respiratory-type lining. Gestational ages ranged from 21 5/7 to 38 2/7 weeks. Patients in groups 1 and 2 were generally younger than those in group 3; however, morphology did not seem to correlate entirely with normal stages of fetal lung development, and group 2 lesions in particular were the least akin to normal fetal lung. In 4 cases a systemic vascular supply to a lobe of lung was identified, providing evidence that such vasculature is embryonic in origin. The histopathology of fetal lung malformations highlights the variability seen in such lesions at all ages, and it is hoped that continued investigations will provide further insight into these enigmatic lesions.

Histologic and Molecular Profile of Pediatric Insulinomas: Evidence of a Paternal Parent-of-Origin Effect.

CONTEXT: Acquired insulinomas are rare causes of hyperinsulinemic hypoglycemia in children and are much less common than focal lesions of congenital hyperinsulinism. The latter are known to be associated with isodisomy for paternally transmitted ATP-sensitive potassium channel mutations on 11p15; however, the molecular basis for pediatric insulinomas is not well characterized. OBJECTIVE: The purpose of this study was to characterize the histopathological and molecular defects in a large group of 12 pediatric insulinomas seen at The Children's Hospital of Philadelphia. RESULTS: Twelve children with insulinomas were seen between 1971 and 2013, compared to 201 cases with focal congenital hyperinsulinism seen between 1997 and 2014. The age of insulinoma patients ranged from 4-16 years at the time of surgery. Features of MEN1 syndrome were present in five of the 12, including four cases with heterozygous mutations of MEN1 on 11q. Immunohistochemical analysis revealed nuclear loss of p57 staining consistent with loss of the maternal 11p15 allele in 11 of the 12 insulinomas, including all five MEN1-associated tumors. Imbalance of the paternal 11p allele was confirmed by single nucleotide polymorphism genotyping and methylation assays of the 11p imprinting control loci in four of five MEN1-associated tumors and six of seven sporadic insulinomas. In addition, single nucleotide polymorphism genotyping revealed extensive tumor aneuploidy beyond chromosome 11. CONCLUSIONS: These data indicate that MEN1 mutations are more common in insulinomas in children than in adults. Aneuploidy of chromosome 11 and other chromosomes is common in both MEN1 and non-MEN1 insulinomas. The novel observation of a paternal parent-of-origin effect in all MEN1 and most non-MEN1 tumors suggests a critical role for imprinted growth-regulatory genes in the 11p region in the genesis of ß-cell endocrine tumors in children.

Clinical and molecular characterization of a dominant form of congenital hyperinsulinism caused by a mutation in the high-affinity sulfonylurea receptor.

Recessive mutations of sulfonylurea receptor 1 (SUR1) and potassium inward rectifier 6.2 (Kir6.2), the two adjacent genes on chromosome 11p that comprise the beta-cell plasma membrane ATP-sensitive K(+) (K(ATP)) channels, are responsible for the most common form of congenital hyperinsulinism in children. The present study was undertaken to identify the genetic defect in a family with dominantly inherited hyperinsulinism affecting five individuals in three generations. Clinical tests were carried out in three of the patients using acute insulin responses (AIRs) to intravenous stimuli to localize the site of defect in insulin regulation. The affected individuals showed abnormal positive calcium AIR, normal negative leucine AIR, subnormal positive glucose AIR, and impaired tolbutamide AIR. This AIR pattern suggested a K(ATP) channel defect because it resembled that seen in children with recessive hyperinsulinism due to two common SUR1 mutations, g3992-9a and delPhe1388. Genetic linkage to the K(ATP) locus was established using intragenic polymorphisms. Mutation analysis identified a novel trinucleotide deletion in SUR1 exon 34 that results in the loss of serine 1387. Studies of delSer1387 in COSm6 cells confirmed that the expressed mutant protein assembles with Kir6.2 and trafficks to the plasma membrane, but it had no (86)Rb efflux ion transport activity. These results indicate that hyperinsulinism in this family is caused by a SUR1 mutation that is expressed dominantly rather than recessively.

Desmoplastic nested spindle cell tumor of liver: report of four cases of a proposed new entity.

We describe a distinctive tumor of the liver in four children composed of nested spindled and epithelioid cells with extensive desmoplasia that we have termed "desmoplastic nested spindle cell tumor of the liver." All four patients were previously healthy. One patient had a presumptive diagnosis of hepatic hemangioma 11 years prior to presentation. Grossly, the tumors were well circumscribed, lobular white masses, ranging from 2.8 to 15 cm in diameter. These tumors were characterized by the presence of cohesive nests of plump, bland spindle cells arranged in short fascicles with an accompanying desmoplastic stroma. Epithelioid areas ranging from palisading epithelioid cells at the periphery of some nests to pseudoglandular and polygonal cells with intercellular bridges were invariably present. Mitotic activity was low. Calcification and ossification were present. Non-neoplastic bile ducts and hepatic elements were seen both within and surrounding the tumor cell nests. Each tumor displayed cytoplasmic reactivity for vimentin, pan-cytokeratin, CD57, and nuclear staining for WT1. Neuroendocrine markers were negative. Ultrastructurally, the tumor cells showed focally well-developed cell junctions, basal lamina, and few cytoplasmic organelles. All tumors were confined to the liver and were resected without complication. Two patients received postoperative adjuvant therapy for presumed hepatoblastoma. The patients are doing well without recurrence at 7.5 years, 7 years, 5 years, and 8 months post-surgery. The morphologic appearance and immunohistochemical profile of these lesions are unique in our experience and represent a new category of pediatric liver tumor.

Fatal congenital hypertrophic cardiomyopathy and a pancreatic nodule morphologically identical to focal lesion of congenital hyperinsulinism in an infant with costello syndrome: case report and review of the literature.

Costello syndrome is characterized by constitutional mutations in the proto-oncogene HRAS, causing dysmorphic features, multiple cardiac problems, intellectual disability, and an increased risk of neoplasia. We report a male infant with dysmorphic features, born prematurely at 32 weeks, who, during his 3-month life span, had an unusually severe and ultimately fatal manifestation of hypertrophic cardiomyopathy and hyperinsulinemic hypoglycemia. Molecular studies in this patient demonstrated the uncommon Q22K mutation in the HRAS gene, diagnostic of Costello syndrome. The major autopsy findings revealed hypertrophic cardiomyopathy, congenital myopathy, and a 1.4-cm pancreatic nodule that was positive for insulin expression and morphologically identical to a focal lesion of congenital hyperinsulinism. Sequencing of KCNJ11 and ABCC8, the 2 most commonly mutated genes in focal lesion of congenital hyperinsulinism, revealed no mutations. While hyperinsulinism is a recognized feature of RASopathies, a focal proliferation of endocrine cells similar to a focal lesion of hyperinsulinism is a novel pathologic finding in Costello syndrome.