Intradiaphragmatic mesothelial cysts.

Primary tumours and cysts of the diaphragm are rare. In a review of the literature Clagett and Johnson (1949) were able to record 30 cases, to which they added four of their own. Of these cases, 18 were malignant and 16 were benign. Primary cysts constituted only a very small proportion of the cases, and in recording a case of mesothelial cyst of the diaphragm Aufses and Oseasohn (1949) stated that they were only able to find records of five other primary cysts in the literature. We have recently encountered a case of mesothelial diaphragmatic cyst; a second almost identical case which was under the care of Mr. Geoffrey Flavell, of the London Hospital, is also reported by his courtesy.