SIGNIFICANCE OF PRE-ANALYTICAL PHASE IN PATHOHISTOLOGICAL DIAGNOSTIC PROCESS – THE ROLE OF LABORATORY TECHNICIAN IN QUALITY ASSURANCE

Abstract

Histopathological analysis is an essential part of formulating the clinical diagnosis and the examination of
tumors and their differentiation can be a great challenge for the pathologist. The latter is expected to assess the
possibility of drug therapy and to give a prognosis for the development of the disease. The process from the
placement of the biopsy specimens in the histology laboratory to the presentation of the finished samples to the
pathologist is entirely in the hands of the histology laboratory technician, and his duties are related to the
identification of the samples and their entry in the histology journals, as well as to the processing of these samples
and preparation of microscopic preparations. That might be a long and multi-stage process. Advances in technology
allow the implementation of new and modern devices that automatically perform a large part of the research.
However, this does not apply to histopathological laboratories, in which only laboratory technicians still carry out
the specific processing and staining.
Defects in the microscopic slides occur even in the best equipped laboratory. Errors can be made at four different
stages:
- at the stage of processing the specimen and preparation of a paraffin block;
- during cutting of the paraffin block;
- during the staining of the microscopic slides;
- during mounting of the specimens.
Depending on the structure of some organs, more special processing may be required - fixation, tissue shaping,
inclusion, etc. Most often such tissues are: lipomas, lymph nodes, curettage, skin, uterus, brain , bone.
Knowing of the possible stages at which errors might occur is important for both the doctor and the laboratory
technician. A well-trained laboratory technician knows the reasons that lead to difficulties and directs his efforts to
avoid or prevent them. Minimizing errors allows working in a calm atmosphere with a minimization of the harmful
influence of the reagents used.