The CAP has dozens of liaisons to various organizations and efforts, and periodically we publish briefs of what the liaisons hear and see in their liaison roles. Our latest, below, is from the chair and a former member of the CAP Standards Committee.
Frank Schneider, MD; William Castellani, MD
July 2025—The International Organization for Standardization (ISO) published a new technical specification, ISO/TS 23824 (Medical Laboratories—Guidance on Application of ISO 15189 in Anatomic Pathology), on the application of ISO 15189 to anatomic pathology. Although structured around the clauses of ISO 15189, the document offers useful guidance, ideas, and concepts applicable to any AP laboratory, including every AP laboratory in the United States that has to comply with CLIA ’88 or CAP Laboratory Accreditation Program requirements.
ISO 15189, Medical Laboratories—Requirements for Quality and Competence, is an international standard, adopted as an accreditation standard by many countries around the world. It applies the principles of quality management to clinical and anatomic pathology laboratories using general requirements for competent performance of testing. In the United States, ISO 15189 has been implemented voluntarily by close to 100 laboratories as an adjunct to CLIA ’88 regulations or CAP accreditation.
ISO/TS 23824 was created to address gaps in the implementation of an ISO 15189 management system in AP since AP was perceived to be different from other laboratory medicine specialties. For example, AP samples are typically solid, unique, and indivisible; the gross structural integrity determines diagnostic features such as margin status; and the examination process almost always involves many, often unrepeatable manual steps that introduce several risk points along the way. Importantly, the analytical examination process is interpretive, performed by humans with intra- and interobserver variability and with no universally accepted biological reference intervals.
ISO/TS 23824 does not impose new or more stringent requirements than ISO 15189. Instead, the document offers guidance for meeting ISO 15189 requirements that might pose challenges for AP laboratories, such as addressing measurement uncertainty, understanding hierarchy and relationships between management system components, managing process requirements, and handling nonconformities (the ISO word for “anything that went not as intended”). A table with two columns comprises much of the document: One suggests actions to meet each ISO 15189 requirement and the other offers examples of risk management in relationship to each ISO 15189 requirement.
ISO 15189 accreditation is by no means required for use of ISO/TS 23824. The specific clauses of ISO 15189 are used to introduce the aspect of the management system and can be related to the requirements of the CAP checklists and CLIA ’88.
Dr. Schneider is chair of the CAP Standards Committee. He is associate professor, Department of Pathology and Laboratory Medicine, Emory University of School of Medicine. Dr. Castellani, formerly of Penn State Hershey Medical Center, is a former member of the Standards Committee.