**1. Introduction**

In 1999, the American Institute of Medicine (now the National Academy of Medicine) published the paper "To Err is Human: Building a Safer Health System" [1], which broadly defines medical error as the inability to complete a planned action or the use of a wrong plan to achieve a goal. Sirota summarizes the document and its implications for pathology. In his chapter, the author considers that the efforts of professional societies, such as the College of American Pathologists (CAP), through the Laboratory Accreditation Program, as well as their councils and commissions, determine the quality standards for the practice of pathology. In professional training, the academic programs and the American Board of Pathology, with their certification mechanism, help to ensure the full competence of the practice of pathology [2].

The year 1989 saw the most famous quality control initiative when the CAP introduced the Q-PROBES Program, which defines quality in terms of practices of laboratory medicine and anatomic pathology. At the same time, 118 Q-PROBES studies have been conducted in

© 2016 The Author(s). Licensee InTech. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. © 2018 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

thousands of hospitals and independent laboratories in the USA, other places from North America, and abroad to identify and describe various experiences. These studies investigate the frequency of errors occurrence: the laboratory participants submit data from the calculation of the normative rates of errors during the laboratory tests. This exchange of information occurs so this knowledge convinces laboratory to abandon practices and behaviors harmful in the process of laboratory tests [3].

indication of ancillary studies when necessary). The analytic phase includes errors in classification, false negative or positives, and in post-analytic phase, and they describe the defective reports (erroneous or missing nondiagnostic information, error in dictation or typing, report delivery and errors related to computer or format, transmission and upload error). During the pre-analytic phase, wrong identification can be responsible for 27–38% of the errors, and specimens-related errors vary from 4 to 10%. In the analytic phase, diagnoses misinterpretation occurs from 23 to 28% of the errors, and in post-analytic phase, the defective report included from 28 to 48% of the errors. This proposed error taxonomy has shown a very good interobserver agreement of 91.4% (*k* = 0.8780; 95% confidence limit, 0.8416–0.9144)

Errors in Surgical Pathology Laboratory http://dx.doi.org/10.5772/intechopen.72919 91

To discuss the errors in pathology, it is essential to conceptualize their goals. Pathology should provide a correct and complete diagnosis, in other words timely, useful, and understandable for the attending physician [8]. Since the goals of pathology are multifaceted, it is easy to understand that there are multiple possibilities for error. The result must be accurate, based on gold standards, and scientifically validated. But what is the gold standard of pathology? Morphology is subjective and affected by the observer's experience. Cytogenetic studies by in situ or molecular hybridization are not applicable to most diseases routinely found in surgical pathology. Therefore, the most appropriate is to determine the accuracy, as a measure of diagnostic adequacy; it suggests that most of the qualified pathologists will agree on a similar diagnosis when analyzing the same specimen. A major or unacceptable variation is the one that will have a great effect on therapy or prognosis, such as in classifying a benign tumor as a malignant one. A smaller, acceptable, or minor variation is the one that has no effect on the treatment that would alter the progression of the disease, with no effect on the prognosis, such as in some subclassifications of benign or malignant tumors. These definitions can be applied to the three pathology goals (correct, complete, timely) [8, 9]. The errors can be further divided into errors of accuracy, that is, how much of the released diagnosis represents the true pathological process and precision errors related to concordances among pathologists in the interpretation of a case [9].

Meier et al. [10] divided the errors of pathological reports into four categories: errors of interpretation, identification, the specimen, and related to the report. A study based on this classification evaluated 73 participating institutions of Q-PROBES with 1688 errors in 360,218 cases of surgical pathology, with a ratio of 4.7 errors/1000 cases. Rates were higher in institutions with pathology residency programs (8.5 vs. 5.0/1000, *p* = 0.01) or when a percentage of cases were reviewed after release (6.7 vs. 3.8/1000, p = 0.10). Interpretation errors were responsible for 14.6% of the cases, 13.3% were identification errors, 13.7% were related to specimen errors, and 58.4% errors were of other modalities. In general, more errors were detected by pathologists (47.4%) than by clinicians (22%). Incorrect interpretations and specimen errors were detected by pathologists (73.5% and 82.7%, respectively, with *p* = 0.001), while identification errors were more frequently detected by other physicians (44.6%, *p* = 0.001). The rates of identification errors were lower when the reports were reviewed by a second pathologist

when applied to amended reports.

**2. Diagnostic errors and concordances in pathology**

Some reasons may explain less attention to errors in medical labs when compared to other medical errors. The higher variability in error during laboratory testing, difficulties in screening all errors, and all steps involved in the total testing process (TTP) can help explain these facts. Besides that, the TTP is more complex and needs cooperation between several health institutions. Surprisingly, physicians and other interested people do not understand full aspects about the harmfulness of errors in laboratory medicine. In addition to that, it is undesirable for laboratory professionals to report and disclose data about errors [4].

The errors in pathology laboratory are so common that in a self-administered mailed survey with 260 practicing pathologists and 81 academic hospital laboratory medical directors, approximately 95% suggested the involvement of any error and only 48% of that professionals believed that current error reporting systems were adequate. Among the factors that might make it less likely that they would disclose a serious error to a patient, the most common was the possibility that the patient would not understand what he or she was being told (*n* = 84, 49.7%) and the physician would not be able to explain the error clearly to the patient (*n* = 68, 40.2%), according to the interviewees' perception. The majority of participants believed that minor and near misses needed to be disclosed to patients (*n* = 120, 72.3% and 34, 20.1%, respectively) [5].

Troxel stands that an expectation from the society of "zero diagnostic error" and the "zero error standard" supported by the US judicial system is unattainable for obvious reasons (6). Surgical pathology laboratory process is much more complex than highly mechanized processes with minimal human participation, such as clinical laboratory analysis. Meier [6] describes the pathology production process in 12 steps. The production process begins with the correct identification of the patients' samples (1), selecting tissue specimens (2), labeling and transport (3), and accession (4). The process continues with the description of steps involving receipt and sampling of specimens (5), fixing, embedding, and cutting section (6), mounting, staining the slides, and labeling them (7), and delivering them to surgical pathologists (8). The process continues at the pathologist's desk—with examining, collating, and interpreting slides (9) and examining the possibilities of ancillary tests or other information (10), the composition of reports, (11) and finally the receipt and interpretation of the report (12). Therefore, the surgical pathology report is a complex task with multiple steps in which there is a possibility of error.

Meier et al. [7] proposed a standardized error classification that until then did not exist in pathology. We describe four types of errors (defective identification, defective specimen, defective interpretation, and defective report), distributed according to the processing step in the laboratory. In the pre-analytic phase, they describe defective identification (patient, tissue, laterality, anatomic location) and defective specimen (loss of the specimen, erroneous in measurement or gross description, floaters, inadequate sampling, and the absence of indication of ancillary studies when necessary). The analytic phase includes errors in classification, false negative or positives, and in post-analytic phase, and they describe the defective reports (erroneous or missing nondiagnostic information, error in dictation or typing, report delivery and errors related to computer or format, transmission and upload error). During the pre-analytic phase, wrong identification can be responsible for 27–38% of the errors, and specimens-related errors vary from 4 to 10%. In the analytic phase, diagnoses misinterpretation occurs from 23 to 28% of the errors, and in post-analytic phase, the defective report included from 28 to 48% of the errors. This proposed error taxonomy has shown a very good interobserver agreement of 91.4% (*k* = 0.8780; 95% confidence limit, 0.8416–0.9144) when applied to amended reports.
