Clinical utility of DNA amplification and sequencing to identify a strain of Mycobacterium avium in paraffin-embedded, formalin-fixed biopsies from an immunosuppressed child.

Nontuberculous mycobacterial (NTM) infections are serious, though rare, in patients with severe combined immunodeficiency who have received bone marrow transplants. A 5-year-old female patient underwent stem cell/bone marrow transplant with disseminated NTM. Real-time polymerase chain reaction (PCR) using a fluorescence resonance energy transfer (FRET) probe for detection and identification of NTM was performed. The FRET-based real-time PCR assay amplified mycobacterial DNA, and the postamplification melt curve analysis classified the organism as a NTM. The pyrosequence of the hypervariable region A definitively identified the infecting organism as Mycobacterium avium. Real-time PCR along with melt curve analysis and pyrosequencing provides faster, definitive identification of mycobacteria, as compared to bacterial culture. In this case report, we emphasize the importance of utilizing molecular means for fast and accurate diagnosis.

Colorectal adenocarcinoma: a pediatric case review with a focus on mismatch repair gene mutations and E-cadherin expression.

Colorectal adenocarcinoma (CRAC) is exceedingly rare in the pediatric population (fewer than 2 cases per 1 million children). There are 2 major categories of pediatric colorectal adenocarcinoma syndromes: polyposis-related and hereditary nonpolyposis colorectal cancer, also known as Lynch syndrome. Germ line mutations in DNA mismatch repair (MMR) genes (eg, MLH1, MSH2, PMS2, MSH6) have been established as the molecular genetic basis of Lynch syndrome. Another prognostic factor in adult CRAC is the reduced expression of epithelial cadherin (E-cadherin), which has been associated with poor outcome in some adult CRAC cases; however, its role in predicting prognoses in pediatric cases remains unclear. Seven pediatric patients with primary CRAC were reviewed. Available molecular genetic test results were evaluated, and immunohistochemical labeling for MMR proteins and E-cadherin were performed on 5 patients. Four of the 5 patients in our study with available paraffin blocks showed loss of MMR protein expression, consistent with Lynch syndrome. In cases stained for E-cadherin, 3 were strongly positive and 2 were weakly positive; however, with the small sample size and the relatively short follow-up period, an accurate correlation between E-cadherin and prognosis cannot be reached with any degree of certainty. Our findings highlight the importance of genetic testing for MMR gene mutations in children with colorectal cancer and suggest further investigation into the prognostic role of E-cadherin in pediatric CRAC.

Nephrogenic adenoma of the bladder in a prune belly syndrome patient: case report and review of the literature.

Nephrogenic adenoma (NA) is a rare lesion of the urinary tract widely considered to be a metaplastic response to urothelial injury. Herein, we present the case of an 8-year-old male with prune belly syndrome who presented with gross hematuria. Investigation revealed a bladder mass; however, upon cystoscopic examination, multiple polypoid lesions were identified. Microscopic examination revealed NA of the bladder. To our knowledge, this is the second reported case of NA of the bladder in association with prune belly syndrome.

Identification of candidate genes for histiocytoid cardiomyopathy (HC) using whole genome expression analysis: analyzing material from the HC registry.

Histiocytoid cardiomyopathy (HC) is a rare but distinctive arrhythmogenic disorder characterized by incessant ventricular tachycardia, cardiomegaly, and often sudden death by age 2 years. The underlying genetic mechanism of HC has eluded researchers for decades. To further identify the potential molecular-genetic bases of HC, molecular analyses of HC hearts and hearts of age-matched controls were performed. Total RNA and genomic DNA were prepared from formalin-fixed, paraffin-embedded cardiac tissue from 12 cases of HC and 12 age-matched controls. To identify genes differentially expressed in HC, whole genome cDNA-mediated annealing, selection, extension, and ligation profiling was performed. TaqMan quantitative polymerase chain reaction confirmed changes in RNA expression. DNA copy number changes were measured by TaqMan copy number variant analysis. Analysis of differential gene expression in HC cases identified 2 significantly downregulated gene sets aligned sequentially along the genome. The 1st gene cluster consisted of genes S100A8 , S100A9 , and S100A12 at 1q21.3c, and the 2nd cluster consisted of genes IL1RL1 ( ST2 ), IL18R1 , and IL18RAP at 2q12.1a. Strong decreases in interleukin 33 expression were also observed. Decreases in copy number of the S100A genes were confirmed by TaqMan copy number variant assays. S100A genes are downstream of the p38-MAPK pathway that can be activated by interleukin 33 signaling. These data suggest a model in which the interleukin 33-IL1RL1/p38-MAPK/ S100A8-S100A9 axis is downregulated in HC cardiac tissue and provide several candidate genes on 1q21.3c and 2q12.1a for inherited mutations that may predispose individuals to HC.

Ciliated hepatic foregut cyst: four case reports with a review of the literature.

Ciliated hepatic foregut cysts (CHFCs) are rare congenital legions that arise from the embryonic foregut. The cysts are formed during fetal development by evagination from their respective portions of the foregut, and are characterized by a ciliated epithelial lining. Approximately 100 cases of CHFC have been reported, of which only 13 were in children. Although CHFC is typically benign, malignant transformation to squamous cell carcinoma (SCC) has been reported in 3 cases. Survival rate after progression to malignancy is poor, as SCC in this setting is biologically aggressive. We present 4 new cases of CHFC in children between 5 months and 17 years old. Our cases are unusual, as some of the cysts exhibit multilocularity and biliary communication, and 2 of our patients were diagnosed under the age of 1. Additionally, 1 of the cysts was 19.3 cm in diameter, making it the largest reported CHFC to our knowledge. Ciliated hepatic foregut cysts should be included in the differential diagnosis of hepatic lesions.

Immunohistochemical characterization of sonic hedgehog and its downstream signaling molecules during human penile development.

Hypospadias is a common congenital anomalies, yet its molecular basis remains unknown. Recent studies have linked perturbations in the Hedgehog signaling pathway to hypospadias. However, the expression of Sonic hedgehog (Shh) has not been reported during genital development. Immunohistochemical staining for Shh and its receptors was applied to 10 human fetal penises ranging from 12 to 29 weeks gestation. The intensity of Shh staining was greatest in the urethral epithelium at 14 weeks gestation, correlating with the time of urethral tubularization. Results suggest a role for Shh in human male genital development.

Mesenteric cystic masses: a series of 21 pediatric cases and review of the literature.

Mesenteric cysts, seen in all age groups, represent a rare cause of benign abdominal masses in children. We reviewed 21 patients with mesenteric/omental cysts. Gross and radiologic images, along with histologic sections, were reviewed to categorize the structures and determine the relationship to the mesentery and intestines. The cysts were composed of multi-loculated dilated channels at the serosal surface consistent with lymphangioma. Most treatment was simple excision, infrequently with intestinal resection. Nineteen patients did well after surgery. One patient developed short-gut syndrome after massive bowel resection, and one patient died immediately after birth due to massive fetal hydrops and heart failure.

Undifferentiated embryonal sarcoma of the liver is associated with mesenchymal hamartoma and multiple chromosomal abnormalities: a review of eleven cases.

Undifferentiated embryonal sarcoma (UES) of the liver is a primitive mesenchymal, malignant neoplasm occurring in children. The link between UES and mesenchymal hamartoma (MH) is controversial. Whether they share the same histiogenesis, representing 2 ends of a spectrum, or are distinct entities is unclear. The genetic aberrations of these neoplasms are not well understood, although a common breakpoint (19q13.4) was recently identified. The purpose of this study was to elucidate immunohistochemical markers that may establish a link between the 2 tumors by reviewing cases of UES and MH. Cases of UES from 1990 to 2008 were identified. Clinical demographics were reviewed. Hematoxylin and eosin staining and immunohistochemical staining for vimentin, alpha-1 antitrypsin, and alpha-fetoprotein were performed. Eleven children were diagnosed with UES. Five cases were seen arising in association with MH, and transitional zones were evident. The mean age at presentation was 10 years. To our knowledge, the 11-month-old patient is the youngest reported case of UES in concurrence with MH. All UES tumor cells were positive for vimentin, diastase-resistant periodic acid-Schiff stain, and alpha-1 antitrypsin. Chromosomal analysis of 3 UES cases, 2 arising with MH, showed complex karyotypes with no involvement of 19q13.4. We suggest a continuum between UES and MH. Although a chromosomal anomaly of 19q13.4 was not identified, a submicroscopic involvement of this locus cannot be excluded. Additionally, our analyses suggest that multiple chromosomal aberrations may be associated with the MH/UES spectrum.

Fibrofatty changes in failed pediatric cardiac allografts.

The pathogenesis of right ventricular fibrofatty changes can be broadly divided into genetic or acquired. The genetic cause is termed arrhythmogenic right ventricular dysplasia, an inherited cardiomyopathy characterized by fibrofatty replacement of the right ventricular myocardium, and represents an underdiagnosed cardiac entity leading to syncope, recurrent ventricular tachycardias, heart failure, and sudden death. Our study demonstrates that fibrofatty changes can also be seen in pediatric cardiac allografts. Conversely, fat replacement without fibrosis may be seen secondary to infectious myocarditis, chronic inflammation, and ischemia and as part of the aging process. We examined 29 failed cardiac allografts to identify the etiology of graft failure. In this study, 4 patients (13%) had severe right ventricular fibrofatty changes, and when compared with control patients, those with fibrofatty changes had a shorter interval from transplant to graft failure, 2.75 years vs 5.45 years (P  =  0.029). Neither body mass index nor other physiologic parameters found on electrocardiography, echocardiography, or cardiac catherization were different between groups. Furthermore, arrhythmias indicative of arrhythmogenic right ventricular dysplasia were not observed in the study group. This study suggests the fibrofatty infiltration in cardiac allografts is a clinically different entity from arrhythmogenic right ventricular dysplasia and has an unknown etiology. Our study findings suggest that identifying fibrofatty infiltrates in cardiac transplant patients during routine right ventricular biopsy can be a predictive factor for shortened life of the pediatric cardiac allograft.

Two case reports of anophthalmia and congenital heart disease: Adding a new dimension to this association.

Anophthalmia is the congenital absence of ocular tissue from the orbit. Many syndromes and malformations (e.g., anophthalmia-esophageal-genital syndrome, Matthew-Wood syndrome, CHARGE syndrome, oculo-facial-cardio-dental-syndome, heterotaxy, and Fraser syndrome) have been associated with anophthalmia. However, its relation with congenital heart disease has not been fully elucidated. In this article, we discuss two cases of patients with anophthalmia and congenital heart defects, and we compare these findings with other syndromes with which anophthalmia has been associated. One of our two patients showed complex congenital heart disease with heterotaxia, polysplenia, and normal lung lobation. These findings may reflect a new dimension of anophthalmia, heterotaxia, and congenital heart disease associations.

A spectrum of phenotypical expression OF Neu-Laxova syndrome: Three case reports and a review of the literature.

Neu-Laxova syndrome is a rare autosomal recessive disorder characterized by severe intra-uterine growth restriction, extreme microcephaly, marked edema with skin restriction, ichthyosis, craniofacial anomalies, limb deformities, and a spectrum of central nervous system malformations. Less than 70 cases have been described since the first report in 1971. To this day the etiology and genetic basis remains unknown. Consanguinity has been reported. Some authors have postulated the syndrome to be a form of neuro-ectodermal dysplasia, while others suggest that it is a malformation syndrome secondary to severe skin restriction. Although the outcome of this syndrome is lethal, a single case of longer survival (6 months) has been reported. The majority of cases are stillborn or die shortly after birth. Thus, it is clear that Neu-Laxova exhibits a spectrum of disease, with varying degrees of phenotypic expression. We are presenting three new cases of Neu-Laxova syndrome; two were stillbirths and one lived for eleven weeks. Our microscopic and post-mortem findings in these three cases display the vast spectrum of this rare syndrome.

NUT midline carcinoma in a newborn with multiorgan disseminated tumor and a 2-year-old with a pancreatic/hepatic primary.

NUT midline carcinoma (NMC) is a rare and aggressive malignant epithelial tumor defined by rearrangement of the NUT gene on chromosome 15. In two thirds of cases, NUT is involved in a balanced translocation with BDR4 on chromosome 19, while in the remaining cases, NUT is rearranged with variant fusion partners such as BRD3. These undifferentiated tumors primarily affect midline structures, usually in the upper aerodigestive tract and mediastinum. Most reported cases have followed a rapidly lethal clinical course. We report the clinical and pathological findings of NMC in the youngest patients identified so far. The 1st case involves a newborn who presented with a supraorbital mass and extensive multiorgan involvement, including the spine, lungs, liver, pancreas, adrenal glands, and subcutaneous tissue. The 2nd patient was a 2-year-old male with an abdominal mass involving the liver and pancreas with pulmonary metastasis. Histopathological analysis of both tumors showed undifferentiated malignant neoplasms, and immunohistochemistry showed positivity for epithelial markers. Both tumors demonstrated t(15;19), and immunohistochemistry with NUT monoclonal antibodies and fluorescent in situ hybridization confirmed NUT rearrangement. The patients died from disease at 1 and 2 months postpresentation. Thus far, 25 cases have been reported, including our 2 current cases. Presentation ages range from 0 to 78 years (mean, 23 years). Herein, we report the 2 youngest reported cases of NMC, including the 1st congenital case and the 1st case arising within the liver/pancreas. Increased awareness and further molecular studies are required for a better understanding of NMC pathobiology and improved therapeutic outcomes.