The concept of a specimen is deeply connected to analysis (lab) workflow, the decisions made during analysis, and the “containers” used within the workflow.
Typical anatomic pathology cases represent the analysis of (all) tissue and/or non-biologic material (e.g., orthopedic hardware) removed in a single collection procedure (e.g., surgical operation/event, biopsy, scrape, aspiration etc.). A case is usually called an “Accession” and is given a single accession number in the Laboratory Information System.
During an operation, the surgeon may label and send one or more discrete collections of material (specimens) to pathology for analysis. By sending discrete, labeled collections of tissue in separate containers, the surgeon is requesting that each discrete labeled collection (specimen) be analyzed and reported independently – as a separate “Part” of the overall case. Therefore, each Part is an important, logical component of the laboratory workflow. Within each Accession, each Part is managed separately from the others and is identified uniquely in the workflow and in the Laboratory Information System.
During the initial gross (or “eyeball”) examination of a Part, the pathologist may determine that some or all of the tissue in a Part should be analyzed further (usually through histology). The pathologist will place all or selected sub-samples of the material that makes up the Part into labeled containers (cassettes). After some processing, all the tissue in each cassette is embedded in a paraffin block (or epoxy resin for electron microscopy); at the end of the process, the block is physically attached to the cassette and has the same label. Therefore, each “Block” is an important, logical component of the laboratory workflow, which corresponds to physical material in a container for handling, separating and identifying material managed in the workflow. Within the workflow and Laboratory Information System, each Block is identified uniquely and managed separately from all others.
From a Block, technicians can slice very thin sections. One or more of these sections is placed on one or more slides. (Note, material from a Part can also be placed directly on a slide bypassing the block). A slide can be stained and then examined by the pathologists. Each “Slide”, therefore, is an important, logical component of the laboratory workflow, which corresponds to physical material in a container for handling, separating and identifying material managed in the workflow. Within the workflow and within the Laboratory Information Systems, each Slide is identified uniquely and managed separately from all others.
While “Parts” to “Blocks” to “Slides” is by far the most common workflow in pathology, it is important to note that there can be numerous variations on this basic theme. In particular, laser capture microdissection and other slide sampling approaches for molecular pathology are in increasing use. Such new workflows require a generic approach in the Standard to identifying and managing specimen identification and processing, not one limited only to “Parts”, “Blocks”, and “Slides”. Therefore, the Standard adopts a generic approach of describing uniquely identified Specimens in Containers.