Enlarge
Donor: Royal Victoria hospital
Date: 1939
Size (H x W x D cm): 20 x 16 x 8
The heart, great vessels and right lung are seen; the left lung is absent. A one cm “diverticulum” representing the rudimentary left main bronchus can be seen at the tracheal bifurcation (A, arrow).
A. Click image to enlarge.
History: Two and 1/2 year-old girl; history unknown.
Comment: The respiratory system begins as an outpouching of the ventral foregut. This develops two lateral lung buds, which elongate and repeatedly divide dichotomously to form the bronchial tree. Failure of a branch to divide leads to absence of distal respiratory tissue. Total agenesis such as seen in this case is rare.