Fixation on Histology

Most Frequent & Simple Labeling Error to Avoid in Low-Resource Setting Histology Labs

Anatomic Pathology Laboratory is where cancer investigation is carried out. It is here, cytology and tissue samples pass through complex procedures to reach the pathologist for interpretation. The pathologist receives stained slides that obtained sections mounted on the slide from the paraffin block. And in the case of cytology samples, they only receive smeared and stained slides. Therefore, it is imperative for these cassettes, blocks, and slides to be identified in a fashion that is informative and clearly understandable to all of the individuals handling that material. This applies to the laboratory and institution where those blocks and slides have been produced and to individuals from other institutions who may be requested to review them for medical care purposes and research as an institutional or personal consultation. 

When a pathologist does grossing in a low-resource laboratory, the grossing description is written either by a resident or a histology laboratory professional. In this case, the cassettes are labeled with a pencil by the person who assists the pathologist. At the embedding step, tissue cassettes may either change or add according to the situation, and labeling at the cassette may also be applied. At the microtomy step where a high labeling error occurred, copy the labeling code from the block and paste it to the microscopic slides that mount tissue sections. In low-resource setting histology laboratories, labeling of cassettes, microscopic slides are done with the help of a pencil. And some factors negatively affect the labeling quality. They are the type of pencil, eligibility of the label by laboratory personnel, type of cassette, type of frosted microscopic slide, and training level of the lab personnel. 

Even though; labeling errors have been categorized as class 1, typographical errors with no clinical consequences; class 2, minor errors unlikely to have clinical consequences; and class 3, errors that are significant and have the potential to impact patient care detrimentally, we histology laboratory professionals consider all labeling errors are fatal. 

Secondly, histology laboratories in LMIC use different from laboratory to laboratory and traditional ways of labeling their blocks and cassettes. As a result, there is no similar communication whenever there is a chance of sample referral and knowledge transfer sessions.

Therefore; experienced institutions like ASCP, NSH and CAP should try their best to share and implement the quality of labeling in a uniform and consistent fashion to avoid potentially serious errors; to increase efficiency in the distribution, examination, filing, and retrieval of the material; and to facilitate communication among institutions. It believes that the error would be reduced if the standard is changed.


  1. Lester Layfield, Gina M. Anderson, Specimen Labeling Errors in Surgical Pathology, An 18-Month Experience Am J Clin Pathol, 2010;134:466-470
  2. Brown et. al, Uniform Labeling of Blocks and Slides in Surgical Pathology, Arch Pathol Lab Med, 2015;139: 1515 - 1524
  3. Scott K, Advanced Standards for Specimen Labeling and Tracking, Clinical Laboratory News, AACC, 2020

Written by:  Giorgis Yeabyo, MCLM, ASCP, HTL, Abeba Consultancy Services | Addis Ababa, Ethiopia

#Laboratory Operations