What should you know about histology and immunohistochemistry?

After a biopsy, a pathologist studies prepared tissue sections. Histology considers the shape, arrangement, and appearance of cells, along with changes in the surrounding tissue. Immunohistochemistry, often shortened to IHC, uses antibodies linked to visible stains. These antibodies bind to selected proteins or other markers when they are present in the sample.

The pattern of staining can support a diagnosis, distinguish one tumour type from another, and sometimes show features that guide treatment choices. A stain is interpreted alongside the tissue appearance and the clinical and imaging information; it is not a stand-alone verdict. Results may be reported as positive, negative, weak, strong, focal, or diffuse, depending on the marker and laboratory method.

Keep the complete pathology report and ask which findings are confirmed, which are still being clarified, and whether additional stains are planned. Ask how the result fits with the biopsy findings and scans. If the wording is unfamiliar, request a plain-language explanation from the treating team or pathology service.

Do not compare a single marker result with another person’s report. Different cancers use different marker panels, and the meaning can depend on the tissue site and the quality of the specimen. If treatment is being discussed, ask whether the IHC findings change the available options or whether another sample is needed.

Contact the clinical team if you have not received the expected pathology follow-up, if the report says that results are pending, or if you do not understand who will explain the findings. Seek urgent medical help for heavy bleeding, worsening pain, fainting, fever, or breathing difficulty after a biopsy, based on the procedure instructions you were given.

Which tissue changes were seen on histology? Which IHC markers were tested, and what did each result add? Does the report establish a diagnosis, or are more tests needed? How will these findings affect staging or treatment planning?