Atypical radiographic findings in neonates with absent pulmonary valve and tetralogy of Fallot.

At birth, three infants had typical to-and-fro murmurs and laboratory features suggesting tetralogy of Fallot with absent pulmonary valve. Initial posteroanterior chest x-ray films were atypical for the condition because of the apparent absence of dilation of the proximal pulmonary arterial tree. Lateral chest x-ray films invariably demonstrated a large hilar mass. Radiographic findings on the posteroanterior chest x-ray film considered pathognomonic for the complex lesion may not evolve until later during the first year of life.