Histopathology is the study of diseased tissues. Most often, biopsy samples of abnormal tissue are submitted for histopathology to determine the presence or absence of disease and, if present, the type and severity of the disease. The information gleaned is used to assist the veterinarian in deciding on the best course of action. Histopathology is often indicated to evaluate lumps, masses, and other abnormal tissues removed from animals.

There are no contraindications to performing this test on any abnormal tissue removed from an animal.

What Does Histopathology Reveal?

Histopathology reveals the types of cells present in abnormal tissue, permitting accurate diagnosis of the disease and helping determine appropriate treatment(s). Where cancer is involved, histopathology helps determine the aggressiveness of the cancer, which assists in coming to a decision how to proceed.

How Is Histopathology Done?

Histopathology is performed on small pieces of tissue removed from a diseased or abnormal part of the body or internal organ. Often, once the sample is obtained, it is placed in formalin. Formalin preserves the tissue and prevents decomposition or decay. This "fixed" tissue is then submitted to a pathologist for analysis. The sample is removed from the formalin and placed in a block of paraffin wax. Then, using a very sharp diamond-edged cutting instrument, the paraffin block encasing the tissue is sliced into extremely thin, nearly transparent, sections. These sections are then placed on slides, sometimes stained, and then examined under a microscope. A written report is generated by the pathologist and sent to the veterinarian. Test results may not be available for 5 to 7 days.

Is Histopathology Painful?

Histopathology is not painful since the procedure is performed on tissue already removed from an animal. However, to obtain the sample to be analyzed, biopsy or "lumpectomy" is required. Each of these may cause some post-procedural pain or discomfort.

Is Sedation or Anesthesia Needed for Histopathology?

Sedation or anesthesia is often needed to obtain the sample to be analyzed.