Cloacal exstrophy: complex lower abd wall defect w herniation of bowel between 2 halves of exposed and splayed bladder. an omphalocele may form the upper portion of this defect.

Gastroschisis: paramidline abd wall defect (usually right); umbilical cord insertion is normal; no sac covers herniated bowel; assoc anomalies are very uncommon except for bowel atresias which maybe 2/2 vascular insults (30% of cases)

• Malrotation is present 100% of cases 2/2 lack of normal mesenteric fixation; herniated bowel is inflamed by chronic exposure to the amniotic fluid and may bhave postnatal dysmotility.

• Immediate postnatal surgical repair is ideal but may require staged closure w external silo device if abd pressures are too high upon the initial attmept to return the viscera to the abd.

Pentalogy of Cantrell: omphalocele and defects in diaphragm, pericardium, and sternum w ectopia cordis

Physiologic gut herniation: bowel normally herniates into the umbilical cord and returns by 12 weeks gestation

Omphalocele: midline abd wall defect w herniation of abd contents into the base of the umbilical stalk. Umbilical cord inserts into the hernia sac that contains the abdominal viscera. Liver and bowel frequently herniate; numerous assoc syndromes and chromosomal anomalies.

Meconium peritonitis: 

Meconium pseudocyt: rim calcified intrabdominal mass displacing bowel loops; following perforation, meconium calcifies w/n 12-14 hours (CF may be less liekly to calcify)

Primary pediatric liver tumors may be classified as: Epithelial / hepatocyte-derived or Mesenchymal

Liver metastasis may be 2/2 neuroblastoma, Wilms tumor, sarcoma, and Burkitt lymphoma

DDX can be narrowed based on 

• Imaging appearance (cystic vs solid)

• Age of patient

  • 0-3 yo: hemangioendothelioma, hepatoblastoma, mesenchymal hamartoma

  • >5 yo: HCC, undifferentiated embryonal sarcoma

  • Any age: metastatic liver tumors like Wilms tumor or neuroblastoma

• Tumor markers (AFP, endothelial GF)

Pediatric vascular malformations vs neoplasms

• Vascular anomalies schemes

  • Neoplasms (new cell growth) & malformations (disorganized vasculature w/o new cell growth)

  • High flow (AVM, AVF) & low flow (venous malformations, lymphatic malformations)

• Hemangioma terminology describes multiple unrelated vascular lesions: infantile hemangioma, potentially malignant hemangioendothelioma, and benign venous malformations

ADRENAL ABNORMALITIES