Renal Tubular Dysgenesis, Neonatal Hemachromatosis and Left Coronary Artery Right Ventricular Outflow Track Fistula: The First Case Report
DW Azar, HF Krous. University of California, San Diego, CA; Rady Children's Hospital, San Diego, CA
Background: Renal tubular dysgenesis (RTD) is characterized by absence of proximal renal tubules and late gestational oligohydramniosis leading to the Potter sequence. Neonatal hemachromatosis (NH), a cause of infantile liver failure, is a gestational condition with liver and extrahepatic iron accumulation. To date, only five cases with combined RTD and NH have been reported, none with a coronary artery ventricular fistula.
Design: A male infant was delivered spontaneously at 35 weeks gestation after discovery of late gestational oligohydramniosis. Workup suggested a possible coronary artery to right ventricular outflow tract fistula and liver lesions. The infant's clinical course was characterized by anemia, thrombocytopenia, coagulopathy, anuria, and persistent respiratory distress leading to his death on day four of life.
Results: Autopsy revealed generalized edema, jaundice, and dysmorphic features consistent with the oligohydramniosis sequence. The 40 gm liver was atrophic. Microscopic examination revealed diffuse hepatocellular loss with lobular collapse, cholestasis and early fibrosis. Iron staining revealed abundant iron within hepatocytes and bile duct epithelium, as well as pancreatic acini and thyroid. The reticuloendothelial system was spared. Although grossly unremarkable, the kidneys revealed near complete absence of proximal renal tubules that was further confirmed by lack of PAS staining and a of lack tubules staining for CD10. The presence of distal tubules, loops of Henle, and collecting ducts was confirmed histologically and by the presence of positive staining for EMA, CD15, and A-AT. Step sections confirmed the presence of a left anterior descending coronary artery to right ventricular outflow tract fistula.
Conclusions: We present the sixth case with combined RTD and NH, and the first with an associated left coronary artery-right ventricular fistula. Although a variety of other abnormalities have been associated with either RTD or NH, none have been reported with cardiovascular malformations. While the etiology and pathogenesis of RTD and NH remain unknown, our case does not provide support for the hypothesis of fetal hypoxemia. A mechanism connecting growth factors relating to renal cardiovascular development with disordered fetal iron metabolism is probably more likely.
Monday, March 9, 2009 9:30 AM
Poster Session I Stowell-Orbison/Autopsy Award # 1, Monday Morning