Contains the papers and slides of Dr. William W. Johnston (1933-) who served as a physician and professor in the Duke University School of Medicine Department of Pathology and later chief of Cytopathology. Types of materials include slides, correspondence, depositions, and research papers. Major subjects include cytopathological diseases and conditions. The collection contains approximately 10,400 slides from approximately 1,100 unique cases. Reference index cards corresponding with the slides are also included in the collection. Materials in this collection range in date from 1964 to 1991.