Quality control in histopathology and diagnostic cytology.

The need for quality control in diagnostic histopathology and cytology is analysed together with a discussion of previously reported experience in this field. The philosophical and mathematical inferences of this type of exercise are debated also in relationship to personally observed experiences in respect of uterine cervical cytology and histology. The desirability of methods of monitoring of diagnostic quality and of obtaining quality improvement are emphasized and suggestions made regarding the techniques most suited to these objectives.