Wilms' tumor and related abnormalities in the fetus and newborn

Congenital segmental dilatation of the intestine in a neonate

A woman in her 30s at 29 weeks of gestation was diagnosed with a fetal abdominal cyst and polyhydramnios. As the cyst gradually increased in size, an elective caesarean section was performed at 38 weeks of gestation. The neonate experienced respiratory distress due to tense abdominal distension shortly after birth. An emergency laparotomy was performed. The intestinal tract was markedly dilated and contiguous with the cyst. The small bowel distal to the dilated intestine had herniated through the defect. The dilated segment was resected, and an ileostomy was created. The operative and histopathological findings suggested segmental dilatation of the intestine (SDI). SDI is a rare gastrointestinal disorder presenting during the neonatal period. It can cause respiratory failure in newborns by compression owing to its large size. SDI should be considered in the differential diagnosis of relatively large abdominal cysts, and collaboration with paediatric surgeons and neonatologists is necessary for successful outcomes.

Fetal abdominal tumors and cysts

This article reviews the contemporary diagnosis and management of the most common abdominal neoplasms and cystic lesions diagnosed in the fetus. Fetal tumors discussed include teratomas (sacrococcygeal, cervical or mediastinal), mesoblastic nephroma, nephroblastoma (Wilms' tumor), neuroblastoma, and hepatoblastoma. Fetal abdominal cystic lesions discussed include ovarian cyst, choledochal cyst, intestinal duplication cyst, mesenteric cyst, simple hepatic cyst, and meconium pseudocyst. We discuss the rare indications for fetal intervention or fetal surgery and other perinatal management, including prenatal interventions and fetal surgery for sacrococcygeal teratoma. The lesions reviewed are detected by widespread use of screening ultrasonography during pregnancy. Work-up for these abnormalities may include fetal MRI which enhances the diagnostic accuracy of abdominal tumors and cystic lesions and can aid in characterization of the lesion in relationship to surrounding anatomic structures. Accurate prenatal diagnosis of such lesions permits recommendations for optimal location and timing of delivery, and inclusion of appropriate caregivers and expertise to facilitate postnatal management. Perinatal management of the fetus with a neoplasm requires consideration of the optimal timing and mode of delivery, and pediatric oncology and surgical specialty care. The majority of tumors diagnosed antenatally have good prognosis with current multimodality treatment.

Inherited Forms of Renal Cell Carcinoma

It is estimated that up to 2% of renal cell cancer (RCC) clusters in families. Several forms of hereditary RCC have been characterized with specific clinical, histopathological, and genetic features. The most common of these is von Hippel-Lindau (VHL) disease caused by mutations in the VHL gene and predisposing to clear cell RCC. Predisposition to papillary RCC is present in hereditary leiomyomatosis and renal cell cancer (HLRCC) and hereditary papillary renal cell carcinoma (HPRC). Identification of the genetic defects causing these diseases has enlightened the molecular pathogenesis of RCC, and moreover, provided means to improve patient management. Genetic testing enables early diagnosis of the disease, after which individuals at-risk can be guided to regular surveillance. Screening facilitates detection of presymptomatic early tumors broadening treatment options and potentially improving prognosis. Thus, identification of individuals with inherited cancer susceptibility is important as special management of these patients improves disease outcome. The purpose of this review is to provide clues for identification and management of hereditary renal cancer patients in clinical practice.

Perlman syndrome: report, prenatal findings and review

Perlman syndrome is a rare overgrowth syndrome characterized by polyhydramnios with neonatal macrosomia, nephromegaly, distinctive facial appearance, renal dysplasia, nephro-blastomatosis, and predisposition to Wilms tumor (WT). We report on a newborn with prenatal sonographic signs of Perlman syndrome, large fetal ascites, nephromegaly and macrosomia. The clinical course was marked by neonatal distress, renal failure and refractory hypoxemia leading to death at 2 days of life. Renal histologic examination showed bilateral nephroblastomatosis. Genetic or epigenetic alterations of the 11p15 region (involved in the BWS), including mutation of the CDKN1C gene were excluded. No mutation of the GPC3 gene was identified. We review the 28 patients who have been reported with Perlman syndrome. The prognosis of Perlman syndrome is poor with a high neonatal mortality rate. Among the infants who survived beyond the neonatal period, 64% developed a WT and all had a developmental delay. Fetal macrosomia, ascites and polyhydramnios are frequent manifestations. Clinical overlaps with other overgrowth syndromes particularly Beckwith-Wiedemann syndrome and Simpson-Golabi-Behmel syndrome have been emphasized. Perlman syndrome is considered as an autosomal recessive condition. We review 19 patients from seven sibships with parental consanguinity in two families only. The other cases were sporadic. The 28 reported patients had only 10 unaffected sibs. The low percentage of consanguinity among parents is also puzzling for a rare recessive condition. The molecular basis of Perlman syndrome is unknown. (Epi)genetic anomalies of 11p15 and mutations in GPC3 were not studied in most of the previous reports.

Identification of limited regions of genetic aberrations in patients affected with Wilms' tumor using a tiling-path chromosome 22 array

Wilms' tumor (WT) is one of the most common solid tumors of childhood. The genetics of this disorder is complex and few studies have suggested allelic loss of chromosome 22 as a frequent aberration. To assess tumor- and possible germline-specific regions affected with gene copy number variations on this chromosome, we applied a high-resolution genomic clone-based chromosome 22 array to a series of 28 WT samples and the paired blood-derived DNA of the patients. The group of tumors was enriched for cases with metastases, relapse or fatal outcome, criteria that were expected to yield a higher number of alterations on chromosome 22. Overall, the array-based form of comparative genomic hybridization (array-CGH) analysis revealed genomic changes in 53% (15 out of 28) of cases. We identified hemizygous deletion of the whole arm of 22q in 3 tumors (11%). Furthermore, a complex amplifier genotype was detected in 8 samples, presenting regions of gain along the chromosome, which defined 7 distinct minimal overlapping segments. The distribution of aberrations in 4 additional cases displaying regional genomic imbalances delimited 2 tumor suppressor/oncogene candidate loci, 1 in the proximal and the other in the terminal part of 22q. Analysis of these regions revealed the presence of several candidate genes that may play a role in the development of WT. These findings demonstrate the power of array-CGH in the determination of DNA copy number alterations and further strength the notion that WT-associated genes exist on this chromosome.

Pediatric genitourinary tumors

Advances in our knowledge of pediatric genitourinary tumors are being made at both the basic science and clinical levels. The molecular mechanisms underlying these pediatric malignancies are being uncovered and will aid in uncovering novel treatments. Because of the high success rate in treating these tumors, treatment options are being modified to decrease both short- and long-term morbidity, while maintaining the improved survival.