Home >> ALL ISSUES >> 2017 Issues >> Pathologist Cognition

Pathologist Cognition

image_pdfCreate PDF

June 2017—In the chapter “Diagnostic Errors and Cognitive Bias” in Patient Safety in Anatomic & Clinical Pathology Laboratories, Stephen S. Raab, MD, writes about pathology work process and cognitive failures, pattern recognition and cognitive strategies, interpretive error, and mitigation and improving safety. Here is his section on pathologist cognition. Dr. Raab is a professor of pathology at the University of Mississippi Medical Center, Jackson.

Most medical practitioners use a form of pattern recognition when rendering a diagnostic opinion. Anatomic pathologists make interpretations of gross tissue and cellular-level disease using the cognitive method of image-based pattern recognition. Clinical pathologists also use image-based pattern recognition in fields such as microbiology, flow cytometric analysis, and transfusion medicine. For a more detailed discussion, anatomic pathology pattern recognition will be discussed.

Fig. 1. A. Qualitative representation of nuclear size in the cells of a cervical intraepithelial neoplasia 1 (CIN I). Each X represents the size of one cell nucleus. The curve represents the frequency distribution of nuclear size in all the cells in the specimen. B. Frequency distribution of nuclear size in four specimens of CIN I. C. Normalized frequency distribution of nuclear size in four specimens of CIN I.

Fig. 1. A. Qualitative representation of nuclear size in the cells of a cervical intraepithelial neoplasia 1 (CIN I). Each X represents the size of one cell nucleus. The curve represents the frequency distribution of nuclear size in all the cells in the specimen. B. Frequency distribution of nuclear size in four specimens of CIN I. C. Normalized frequency distribution of nuclear size in four specimens of CIN I.

For this process at a cellular level, a pathologist makes a diagnosis of a specific disease by (1) visually examining a cellular-level image obtained from a patient’s bodily tissue (stimulus detection), (2) breaking down the stimulus into component characteristics (eg, assessing for the presence of criteria), and (3) associating a specific combination of observed morphologic criteria with that specific disease (feature comparison and recognition). A pathologist may use additional data—such as clinical history, radiologic impressions, or other inputs—in the decision-making process. These data often construct a specific context in which the pattern recognition occurs.

Gross tissue examination also involves pattern recognition, which generally results in producing descriptive data that are used later in cellular disease decision making and inform sectioning protocols.

Pathologists generally learn gross and cellular-level pattern recognition in an apprenticeship environment in which pathologists with more expertise (masters) teach these patterns of criteria and the associated diagnosis of a specific disease to less experienced pathologists or trainees (novices).

Using the process of pattern recognition, a pathologist examines a tissue slide and looks for criteria of normality and abnormality within the tissue. Pattern recognition depends on linking the observed patterns of criteria with knowledge of mental maps of patterns of criteria that represent specific diseases. The presence of normal tissue in the same sample, for comparison, is often useful.

A criterion describes (1) a specific characteristic of a cell (eg, morphologic feature of color, size, shape); (2) the specific arrangement of cells (eg, small clusters, sheets, glandular-like structures); or (3) the specific tissue architecture or relationship of cellular and noncellular components (eg, invasion, necrosis, microcalcification). Table 1 shows examples of typical criteria observed in a patient who has cervical intraepithelial neoplasia 1 (CIN I). This is not an exhaustive list of criteria because, in actuality, the individual cells, cellular arrangements, and cellular relationships display a large variety of appearances.

Some criteria are more important than other criteria in making a diagnosis, as these criteria are more representative of a group of diseases or a specific disease.

CAP TODAY
X