How to Name Papillary Tumors of the Bladder in Children: Transitional Cell Carcinoma or Papillary Urothelial Neoplasm of Low Malignant Potential?

Urinary bladder malignancies are uncommon in children. Approximately 80 children with papillary carcinoma have been described to date, presenting as papillary neoplasms of both low grade and low stage. On the basis of the 1973 World Health Organization classification, tumors were classified as transitional cell carcinoma of the urinary bladder (TCCB). Owing to more detailed histologic criteria, this term has been replaced by papillary urothelial neoplasm of low malignant potential and low-grade carcinoma of the urinary bladder in the World Health Organization-International Society of Urologic Pathology consensus classification system of urothelial neoplasms 2004. Nevertheless, TCCB still remains a common term in contemporary literature. Thus, the differences between papillary urothelial neoplasm of low malignant potential, low-grade carcinoma of the urinary bladder, and TCCB will be illustrated by means of 4 examples of pediatric patients with papillary tumors.

Haploinsufficiency of the NOTCH1 Receptor as a Cause of Adams-Oliver Syndrome With Variable Cardiac Anomalies.

BACKGROUND: Adams-Oliver syndrome (AOS) is a rare disorder characterized by congenital limb defects and scalp cutis aplasia. In a proportion of cases, notable cardiac involvement is also apparent. Despite recent advances in the understanding of the genetic basis of AOS, for the majority of affected subjects, the underlying molecular defect remains unresolved. This study aimed to identify novel genetic determinants of AOS. METHODS AND RESULTS: Whole-exome sequencing was performed for 12 probands, each with a clinical diagnosis of AOS. Analyses led to the identification of novel heterozygous truncating NOTCH1 mutations (c.1649dupA and c.6049_6050delTC) in 2 kindreds in which AOS was segregating as an autosomal dominant trait. Screening a cohort of 52 unrelated AOS subjects, we detected 8 additional unique NOTCH1 mutations, including 3 de novo amino acid substitutions, all within the ligand-binding domain. Congenital heart anomalies were noted in 47% (8/17) of NOTCH1-positive probands and affected family members. In leukocyte-derived RNA from subjects harboring NOTCH1 extracellular domain mutations, we observed significant reduction of NOTCH1 expression, suggesting instability and degradation of mutant mRNA transcripts by the cellular machinery. Transient transfection of mutagenized NOTCH1 missense constructs also revealed significant reduction in gene expression. Mutant NOTCH1 expression was associated with downregulation of the Notch target genes HEY1 and HES1, indicating that NOTCH1-related AOS arises through dysregulation of the Notch signaling pathway. CONCLUSIONS: These findings highlight a key role for NOTCH1 across a range of developmental anomalies that include cardiac defects and implicate NOTCH1 haploinsufficiency as a likely molecular mechanism for this group of disorders.

Development of the human male urethra: a histochemical study on human embryos.

PURPOSE: Controversy persists regarding the formation of human penile urethra. The classic fusion theory for the development of the spongy urethra and ectodermal ingrowth or endodermal transformation theories for the development of the glanular urethra do not explain the wide spectrum of anomalies seen in patients with hypospadias. This histological study was made to clarify the mechanism of urethral development. MATERIALS & METHODS: 15 human male embryos ranging from 6 to 14 weeks were studied. The phalluses were examined microscopically and photographed. Tissues were prepared as serial histological sections and stained with haematoxylin and eosin and with special immuno-histochemical stains. RESULTS: 1) The penile urethra: At 6 weeks of gestation, the urethral plate which is solid distally and partially grooved proximally becomes grooved distally and has fused proximally by 8 weeks. At 14 weeks of gestation; the urethral opening migrates only to the middle of the shaft. 2) The glanular urethra: At the 6th week of gestation, a solid epithelial plate reached the tip of the genital tubercle, and a glans cannot be identified. At the 7th week, a central vacuolation appears and the penile urethral groove does not reach the tip of the phallus. At the 8th week; coronal sulcus starts to appear, and a well defined blind central canal was evident in the 13th week. During the 14th week, the floor of the glanular canal degenerated to form a glanular groove. CONCLUSIONS: Our observations suggest that the spongy urethra passes through 3 stages of development: a solid epithelial plate, deep urethral groove, and fused urethra. The glanular urethra passes through 4 developmental stages: a solid epithelial plate, a blind central canal, a deep glanular groove, and the floor from the preputial lamella. There was no evidence of ectodermal ingrowth. These observations raise serious questions to the current theories for human urethra development. Further studies on fresh human embryos are needed.

Case report: Noonan syndrome with multiple giant cell lesions and review of the literature.

Noonan syndrome with multiple giant cell lesions (NS/MGCL) was recently shown to be a phenotypic variation within the syndromes of the Ras/MAPK pathway and not an independent entity as previously thought. Here we report on a 13-year-old boy with a typical phenotype of NS including atrial septal defect, pulmonic stenosis, short stature, and combined pectus carinatum/excavatum, pronounced MGCL of both jaws, and a de novo mutation in PTPN11, c.236A>G (which predicts p.Q79R). Mutations in PTPN11 are the most frequent cause of NS and p.Q79R is a recurrent mutation in exon 3. Including this patient, 24 patients with molecularly confirmed NS, LEOPARD, or CFC/MGCL syndrome have been reported to date, of these 21 patients have PTPN11, SOS1, or RAF1 mutations and three have BRAF or MAP2K1 mutations, confirming that MGCL is a rare complication of the deregulated RAS/MAPK pathway. In all patients, the lesions of the mandible and to a lesser extent of the maxilla were first noted between ages 2 and 19 years (median 11 years), and were combined with enlargement of the jaws in 11/24 patients (46%). In this case and, with one exception (mutation not reported), all previous cases the NS/MGCL was caused by known mutations in the PTPN11, SOS1, RAF1, BRAF1, and MAP2K1 genes that were previously reported with RASopathies without MGCL.

Pectus excavatum: history, hypotheses and treatment options.

Pectus excavatum and pectus carinatum represent the most frequent chest wall deformations. However, the pathogenesis is still poorly understood and research results remain inconsistent. To focus on the recent state of knowledge, we summarize and critically discuss the pathological concepts based on the history of these entities, beginning with the first description in the sixteenth century. Based on the early clinical descriptions, we review and discuss the different pathogenetic hypotheses. To open new perspectives for the potential pathomechanisms, the embryonic and foetal development of the ribs and the sternum is highlighted following the understanding that the origin of these deformities is given by the disruption in the maturation of the parasternal region. In the second, different therapeutical techniques are highlighted and based on the pathogenetic hypotheses and the embryological knowledge potential new biomaterial-based perspectives with interesting insights for tissue engineering-based treatment options are presented.

Spatial, temporal and interindividual epigenetic variation of functionally important DNA methylation patterns.

DNA methylation is an epigenetic modification that plays an important role in gene regulation. It can be influenced by stochastic events, environmental factors and developmental programs. However, little is known about the natural variation of gene-specific methylation patterns. In this study, we performed quantitative methylation analyses of six differentially methylated imprinted genes (H19, MEG3, LIT1, NESP55, PEG3 and SNRPN), one hypermethylated pluripotency gene (OCT4) and one hypomethylated tumor suppressor gene (APC) in chorionic villus, fetal and adult cortex, and adult blood samples. Both average methylation level and range of methylation variation depended on the gene locus, tissue type and/or developmental stage. We found considerable variability of functionally important methylation patterns among unrelated healthy individuals and a trend toward more similar methylation levels in monozygotic twins than in dizygotic twins. Imprinted genes showed relatively little methylation changes associated with aging in individuals who are >25 years. The relative differences in methylation among neighboring CpGs in the generally hypomethylated APC promoter may not only reflect stochastic fluctuations but also depend on the tissue type. Our results are consistent with the view that most methylation variation may arise after fertilization, leading to epigenetic mosaicism.

Extreme methylation values of imprinted genes in human abortions and stillbirths.

Imprinted genes play an important role in fetal and placental development. Using quantitative bisulfite pyrosequencing assays, we determined the DNA methylation levels at two paternally methylated (H19 and MEG3) and four maternally methylated (LIT1, NESP55, PEG3, and SNRPN) imprinted regions in fetal muscle samples from abortions and stillbirths. Two of 55 (4%) spontaneous abortions and 10 of 57 (18%) stillbirths displayed hypermethylation in multiple genes. Interestingly, none of 34 induced abortions had extreme methylation values in multiple genes. All but two abortions/stillbirths with multiple methylation abnormalities were male, indicating that the male embryo may be more susceptible to excess methylation. Hypermethylation of multiple imprinted genes is consistent with stochastic failures of the mechanism, which normally protects the hypomethylated allele from de novo methylation after fertilization. Two of six informative abortions/stillbirths with H19 hypermethylation revealed significant biallelic expression of the autocrine growth factor IGF2. In two other cases hypermethylation of MEG3 was associated with transcriptional down-regulation. We propose that primary epimutations resulting in inappropriate methylation and expression patterns of imprinted genes may contribute to both normal human variation and disease, in particular spontaneous pregnancy loss.

Quantitative methylation analysis of developmentally important genes in human pregnancy losses after ART and spontaneous conception.

To study possible effects of assisted reproductive technologies (ART) on epigenetic reprogramming, we have analyzed the DNA methylation levels of differentially methylated regions (DMRs) of seven imprinted genes (H19, MEG3, LIT1, MEST, NESP55, PEG3 and SNRPN) as well as the promoter regions of the pluripotency gene NANOG and the tumor suppressor gene APC in chorionic villus samples (CVS) of 42 spontaneous miscarriages and stillbirths after ART and 29 abortions/stillbirths after spontaneous conception. We did not find an increased rate of faulty methylation patterns after ART, but significant and trend differences (ROC curve analysis, Wilcoxon test) in the methylation levels of LIT1 (P = 0.006) and H19 (P = 0.085) between ART and non-ART samples. With the possible exception of NANOG, we did not observe a gestational age effect on the methylation levels of the studied genes. The frequency of extreme methylation values in PEG3 and APC was markedly higher than in the other studied genes, indicating an increased susceptibility of some genes to epigenetic alterations. Most methylation abnormalities in CVS represented either hypermethylated DMRs of paternally and maternally imprinted genes or hypomethylated promoters of non-imprinted genes. The observed methylation abnormalities (mosaicism) are consistent with methylation reprogramming defects during early embryogenesis.

Bilateral cystic pulmonary glial heterotopia and palatinal teratoma causing respiratory distress in an infant.

We report on a male infant with extensive, bilateral cystic and solid lung lesions who presented postnatally with respiratory distress caused by bilateral cystic lung lesions. Parenchyma-sparing resections were performed. Histology revealed the presence of neuroglial cell-lined cysts and glial nodules. In addition, a neural element containing palatinal teratoma was detected and excised. Based on previously published cases, the pathogenesis and clinical features of pulmonary neuroglial heterotopia are discussed.

Human papilloma virus (HPV)-associated gynecological alteration in mothers of children with recurrent respiratory papillomatosis during long-term observation.

BACKGROUND: Human papilloma virus (HPV) is one of the most frequently observed sexually transmitted infections. The study' purpose was to investigate the relation between a mother's gynecological history and the local status of her child with recurrent respiratory papillomatosis (RRP). METHODS: Forty-two patients enrolled in a prospective multicenter study between 1983 and 1990. The study included patients with juvenile-onset and adult-onset RRP. All patients underwent surgery and treatment with alpha-interferon. Thirty-eight patients were followed up until 31.01.2006. Twenty-five mothers of these patients participated in a parallel prospective study of genital HPV infection. In 1989-1990, all received a routine gynecological examination, an expanded colposcopy, a Pap smear, and a cervical biopsy. The mothers were followed up until February 2006. RESULTS: 74% of patients with RRP were the first-born children. Five (20%) mothers had condylomata acuminata, newly diagnosed during pregnancy. Indicators of HPV infection such as koilocytes, koilocytotic dysplasia and condyloma acuminatum were revealed cytologically in 17% of cases and histologically in 71.4% of cases. Six (24%) of mothers had had a hysterectomy. HPV type 11 was prevalent in the children of mothers who had had a hysterectomy. Among the patients with juvenile-onset RRP, the death rate from squamous cell carcinoma of the lung was significantly higher in those patients whose mothers had a hysterectomy (p=0.028). CONCLUSIONS: Mothers of patients with RRP demonstrated cytological and histological indicators of HPV infection in the genital tract. An adverse outcome of the disease in the child was associated with adverse gynecological history in the mother.

Medullary thyroid carcinoma in a 2-month-old male with multiple endocrine neoplasia 2B and symptoms of pseudo-Hirschsprung disease: a case report.

A 5-week-old male patient was seen for symptoms suggestive of Hirschsprung disease (abdominal distension, failure to thrive, and explosive defecation). Rectum biopsies revealed an intestinal ganglioneuromatosis, which is usually associated with multiple endocrine neoplasia (MEN) syndrome type 2B. The ensuing molecular genetic analysis revealed a M918T mutation of the RET protooncogene, which is associated with early-onset medullary thyroid carcinoma (MTC). Therefore, total thyroidectomy and central lymphadenectomy were performed at the age of 9 weeks. Histology showed a medullary microcarcinoma. This report of MTC occurrence within the first weeks of life underlines the importance of early diagnosis and thyroidectomy in patients with MEN 2B syndrome. Because many patients with MEN 2A and B show gastrointestinal symptoms before the development of MTC, the possibility of MEN 2 should be recognized, and genetic testing for the presence of RET mutations should be included in the explorative diagnosis for megacolon.

T-/H-cadherin (CDH13): a new marker for differentiating podocytes.

Cadherin molecules are known to be involved in various biological processes other than cell adhesion such as morphogenesis, cell-cell communication, cell recognition or cell signalling. While the classical cadherin molecule is characterized by an extracellular moiety, a transmembrane region and a variable cytoplasmic domain, T-/H-cadherin differs from this pattern due to the absence of a transmembrane region and a cytoplasmic domain, respectively. Its extracellular moiety is bound to the apical cell membrane by a glycosyl-phosphatidyl-inositol anchor and localized to lipid raft domains. As its molecular function and expression pattern is still not fully understood, we used a newly generated anti-T-/H-cadherin antiserum to study immunohistochemically the expression of T-/H-cadherin during the differentiation of foetal human glomeruli. At the early capillary loop stage a strong apical signal comes up for visceral epithelial cells of Bowman's capsule, which begin to differentiate towards podocytes. At the advanced capillary loop stage, when podocytes have become part of the glomerular filtration barrier, the expression pattern, however, becomes more distinct and most likely restricted to the foot processes of the podocytes. We thus postulate a functional role of T-/H-cadherin for the differentiation of the podocytes and the formation of the glomerular capillary network.

Quantitative morphometric analysis of the submucous plexus in age-related control groups.

An increased number and density of the so-called "giant ganglia" (seven or greater ganglion cells per ganglion) serve as histopathological criteria for a bowel motility disorder called intestinal neuronal dysplasia of the submucous plexus (IND B). However, because these morphological criteria have been defined based upon observations in constipated patients, the diagnostic value of previous studies is open to controversy. Moreover, no age-related reference data from unaffected controls are available. This study reports on data from unaffected controls on the variability of size and distribution of ganglia in the submucous plexus during development. Therefore, for the first time, the normal status has been defined. Four age groups have been defined: (a) premature births, gestational age less than 35 weeks; (b) 1-365 days; (c) 1-14 years and (d) 15 years to greater than 70 years). All of these groups revealed giant ganglia in the submucous plexus. With advancing age, there was a decrease in the number of giant ganglia (from 32.7% in group a to 11.2% in group d) accompanied by an inverse increase in the mean distance between all ganglia (from 0.52 mm in group a to 1.17 mm in group d). The data presented permit the conclusion that the criteria mentioned above are not apt to define IND B as an entity, since they do not allow a sufficient demarcation from the age-correlated normal values presented here.