Very thorough knowledge of breast pathology is a sine qua non for interpretation of breast films ... progress in X-ray diagnosis could only be made by careful comparison of the film with the actual specimen. H.INGLEBY Multiplication of the same e"oneous diagnosis does not make that diagnosis co"ect. J.G.AzZOPARDI Paradoxically enough, our specialty considers the radiologist who mis­ takes a skin fibroma or the calcifications in a sponge kidney for a kid­ ney stone to lack basic knowledge, while the radiologist who imme­ diately calls for the surgeon because of a few white spots on a mammogram is thought to be acting according to the rules of medical practice. Misunderstandings and confusion with regard to breast pathology as well as the comfortable philosophy that superfluous biopsies are the price we have to pay for the early detection of carcinomas have in many places led to a loss of confidence in mammography. Yet this is a meth­ od with which carcinomas can be detected earlier than with any other imaging technique.