Retrospective analysis of 1500 mamma biopsies from 1951-1975. A way of self-control in pathology

Recently, doubts have been raised regarding the accuracy of histopathological diagnosis. For reasons of quality control, three groups of 500 mamma biopsies each, covering the consecutive periods 1951-1953, 1963-1964, 1975 were re-examined microscopically. The quota of error for material re-diagnosed as false-positive or false-negative was 0.13%. 23 pre and early malignant alterations, formerly "suspected" cases and descriptive diagnoses were considered as "borderline" cases, and re-examined separately by 3 different pathologists. In only 4 cases the suspected malignancy, i.e. the diagnosis of so-called CLIS, was not confirmed. A relative increase of unsuspected mamma biopsies became apparent in the last period of investigation, possible due to the wide range of pre-surgical examination methods used today, or to increasing clinical efforts to detect pre-malignant alterations. No shift could be established in the mastopathy-group.