Adenomatoid hamartoma of the lung in a newborn infant.

In pulmonary pathology the term "hamartoma " is most commonly applied to a group of tumours in adults which usually contain cartilage as a constituent and arise from connective tissue (Sutherland, Aylwin, and Brewin, 1953). Willis (1958) does not think such growths are named correctly and gives good reasons for regarding them as acquired mixed tumours. On the other hand the mass replacing the entire upper lobe of the right lung of a newborn infant reported by Jones (1949) does seem to have been a true hamartomd in which interstitial elements predominated. Another type of hamartoma was described by Ch'in and Tang (1949) as " congenital adenomatoid malformation." These authors considered their case to be the first in the English lapguage, there being 10 previous reports in German. The condition, however, could be included in the category of " mixed tumours " as defined by Womack and Graham (1938) and undoubted examples were reported by Harris and Schattenberg (1942) under the names " anlagen and rest tumours." Thomas's case (1949) of "cystic hamartoma " in a newborn infant also falls into this group, and so does the "diffuse hamartoma" of the left upper lobe of a girl aged 7{ weeks which was successfully removed at thoracotomy and reported by Graham and Singleton (1955). An example is presented here in a newborn premature infant of this second type of hamartoma which involved the whole of the right lung whilst the left lung also showed imperfect development.