A biopsy involves removal of a sample of tissue from a suspected pathological lesion. The tissue may be small in amount, for example, in fine needle aspiration biopsy. Or the tissues may be large in amounts, for example, removal of the entire lesion along with healthy margins as seen in excisional biopsy.
Who performs biopsy analysis?
Biopsy analysis requires the skill of a highly trained doctor called a Pathologist. A pathologist specializes in the diagnosis of disease based on the analysis and visualizing the microscopic amounts of tissue samples under the microscope.
Processing the tissue specimen
Once the tissue is obtained for biopsy it is preserved in formalin or similar chemicals and transferred to the laboratory. This is done to preserve the structure of the tissue and prevent degradation or microbial infestation.
The tissue is then frozen into a block of wax or similar substance. The block is then sliced into microscopically thin slices. Each of the slices are as thick as a single cell. The thin slice is then placed on a glass slide. The remaining tissue is stored for further studies, if required.
The slide is then fixed (so that the tissue slice) remains attached to it and stained with special dyes. These dyes are special because they attach to certain parts of the cell giving them a characteristic appearance.
The most commonly used stain is the Hematoxylin and eosin stain (H&E stain or HE stain). This stain shows up as blue color in the nucleus of the cell and the rest of proteins and body of the cell stains pink or red. Other stains include PAS, MVB, Congo Red etc.
Preparation of report
Staining and examination under the microscope enables the pathologist to see the exact structure of the tissue sample. Based on the findings, the Pathologist prepares a written report that will list any abnormalities or important findings.
Discussion and planning treatment
After the preliminary report from the pathologist the report needs to be co-ordinated with the clinical features and findings of the diseases. The attending doctor will then explain and discuss the results of the biopsy with the patient and his or her family. Based on this the diagnosis and treatment regimen is planned for individual patients.
Reviewed by April Cashin-Garbutt, BA Hons (Cantab)