Patient Safety Tip of the Week

October 9, 2007    

Errors in the Laboratory



Last week a 35 year old woman from Long Island, New York appeared on Good Morning America to discuss her tragic case that resulted from misidentification of a biopsy specimen. She had a double mastectomy after a tissue sample from a lab based in New York came back positive for breast cancer. Doctors later told her she did not have breast cancer and "never did", she said on the TV program. Apparently there was a "lab mixup".

The New York State health department reported that the biopsy sample had been mislabeled by a technician at a pathology laboratory, probably because the technician was handling more than one specimen at a time. The report said the technician admitted to his supervisors that he "occasionally cut corners by batching" and did not always verify patients' initials when labeling them.



A very similar case is noted in “Meeting the Joint Commission’s 2007 National Patient Safety Goals”1. And an article about the current case in Newsday2 includes the description of a second recent case where a woman unnecessarily received radiation therapy for a cancer she did not really have. Undoubtedly there are many more comparable examples. We could not find any published error rates for misidentification of biopsy specimens but one study looking at surgery in an outpatient clinic or a hospital operating room found 4.3 surgical specimen identification errors in every 1000 cases (and about 60% of those errors were in biopsies) 3. Rates for incorrectly identifying hospitalized patients prior to collection of blood specimens have been found to be as high as 6.5%4.



The Joint Commission standard on patient identification requires use of at least 2 patient identifiers (neither of which is the patient’s location). In addition, all containers must be labeled in the presence of the patient. And for laboratories there must be a process in place to maintain the sample’s identity throughout the preanalytical, analytical, and postanalytical processes. However, laboratories should not automatically reject specimens lacking the 2 discrete identifiers because some samples may be irretrievable (such as biopsy specimens). In such cases the laboratory should have written guidelines on how to handle these specimens and the laboratory report should include a cautionary statement indicating the lack of complete identification. Importantly, prelabelling of collection containers is not to be done. Since specimen collection is often performed by personnel outside the laboratory, Joint Commission stresses education and inservicing of all personnel involved plus appropriate monitoring/auditing of the processes.



For Joint Commission-accredited hospitals the Joint Commission standards apply to the laboratory even if the laboratory is not specifically accredited by Joint Commission. However, a growing number of procedures with pathological specimens are being performed outside the hospital setting, not only in ambulatory surgery centers but in physician offices. The latter are often sending specimens to private or commercial laboratories that are not subject to the Joint Commission standards. Most such laboratories are otherwise accredited or certified (eg. by CAP or CLIA). When multiple organizations are involved the preanalytical, analytical and postanalytical phases, we suspect the likelihood of error is even higher.



While there is a lack of systematic reporting on such incidents, much can be gleaned from individual case reports. In one such case5, a pathologist noted a discrepancy among specimens submitted from several sites on the same patient. Specifically, the histological appearance suggested that specimens labeled “wrist” and “back” had been transposed and one of them showed a melanoma. When the pathologist contacted the physician who performed the biopsies, it turned out the patient was the physician’s spouse and that the procedures had been performed on a Sunday when the office was closed and no support staff were available. The specimens had been place in formalin-filled biopsy bottles, prelabeled with the biopsy sites and the requisition sheets were labeled only the following day by the nurse.



Another case6 involving transposition of prostate biopsy specimens from two patients used a detailed root cause analysis (RCA) that uncovered multiple contributing factors and suggested several improvements to processes. These included not only steps to ensure a “one-by-one” accessioning process but also improvements in dictation and transcription and what to do once such an error is identified. Note that this lab used molecular testing to confirm the transposition of specimens and correctly match up the specimens with the correct patient. See below for more on use of DNA techniques in laboratory identification of patients.



Some circumstances that may increase the likelihood of specimen mislabeling include:

·        Multiple specimens on the same patient

·        Multiple specimens on different patients being transported at the same time

·        Multiple specimens being accessioned at the laboratory at the same time

·        Specimens arriving near closing deadlines

·        “Rush” specimens

·        Procedures (eg. biopsies) being done outside of normal hours

·        Procedures being done in site other than hospital operating room

·        Specimens coming from a different physical location



Potential solutions include barcoding (of patient and biopsy bottles), ensuring adequate clinical information and descriptions accompany the specimens, strict one-by-one accessioning of specimens, and regular auditing of processes.



In cases where misidentification of specimens is suspected, some labs have used DNA testing to verify the correct match of patient to specimen. In fact, some have gone as far as to propose universal use of DNA polymorphic microsatellite analysis to confirm patient identification before invasive treatement in patients undergoing biopsies such as prostate biopsies7.



So what should a patient do?  You should ask such questions as: Where will my biopsy specimen be evaluated? Is that lab accredited? By whom? Will any other specimens be being sent along with mine? How and when will I be notified of the result? (And if the specimen is being sent to a lab other than a hospital-based lab, we recommend you also inquire about any financial arrangements between the physician and the lab.)



What should a physician do? He/she should ensure that all staff in his office/facility fully understand the processes involved in specimen collection, identification, and transport. The specimen handling should be done with the same diligence that one uses during surgical timeouts. He/she should have a good understanding of the steps that the laboratory takes to ensure patient identification is maintained throughout. He/she should always provide a good clinical description of the patient and what is being looked for on the specimen(s). When pathology reports note something unexpected, call the lab to discuss the possibility of misidentification and discuss whether a molecular/DNA technique to confirm correct identity should be considered.



Also remember that misidentification of a laboratory specimen impacts two patients (in today’s index case, not only did the patient receive unnecessary treatment but there obviously was a second patient who did have cancer and we are not told if she received appropriate and timely treatment).  So it is imperative in such cases to double check to see whether two errors have occurred.



By the way, you’d be surprised at how often errors take place in cases where a physician is treating one of his/her own family members. The scenario above, where a procedure is done after-hours and without proper personnel present, is one we have seen on numerous occasions. The AMA has guidelines on physician treatment of family members and we feel strongly that the anecdotal evidence of errors in such circumstances is an even more cogent reason for physicians not to treat their own family members.





Update: See also our November 16, 2010 Patient Safety Tip of the Week “Lost Lab Specimens”, which also contains some other good articles on mislabeling and mixups of surgical specimens (Layfield 2010, Lippi 2009, Nakhleh 2003, Valenstein 2004, Astion 2006).









1.      Makary MA, Epstein J, Pronovost PJ et al. Surgical specimen identification errors: A new measure of quality in surgical care. Surgery 2007; 141: 450-455

2.      Grayson A (ed.), Meeting the Joint Commission’s 2007 National Patient Safety Goals. Oakbrook Terrace, IL: Joint Commission Resources. 2006: pp. 13-14

3.      Epstein RJ. Lab mix-up leads to unnecessary double mastectomy. October 3, 2007.,0,6442227.story,0,6442227.story

4.      Howanitz PJ, Errors in laboratory medicine. Practical Lessons to improve patient safety. Arch Pathol Lab Med 2005; 129: 1252-1261 ([1252:EILMPL]2.0.CO;2)

5.      Jukic DM. Pathologist as the Final Quality Assurance Officer, or “The Buck Stops Here”. Pathology Case Reviews 2005; 10: 88-94

6.      Dhir R, Condel JL, Raab SS. Identification and Correction of Errors in the Anatomic Pathology Gross Room. Pathology Case Reviews 2005; 10: 79-81

7.      Suba EJ, Pfeifer JD, Raab SS. Patient Identification Error Among Prostate Needle Core Biopsy Specimens – Are We Ready for a DNA Time-Out? Journal of Urology 2007; 178: 1245-1248







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