What should you know about trap immunohistochemistry?

Immunohistochemistry uses antibodies linked to a visible marker to look for a chosen protein or enzyme in cells. TRAP refers to tartrate-resistant acid phosphatase. A pathologist applies the stain to thin sections from a biopsy or another tissue specimen and examines the pattern and location of staining under a microscope.

A TRAP result is one piece of the pathology assessment. The meaning depends on the tissue type, the appearance of the cells, other stains and the clinical question. A positive or negative stain should not be interpreted alone as proof that a tumour is present or absent.

Ask which specimen was tested and why TRAP staining was selected. Review the wording with the clinician who knows your symptoms, imaging and other pathology findings. If the result is unclear, the team may use additional stains, review the slides or request another pathology opinion.

You do not need to prepare physically for a stain performed on tissue already collected. Keep a copy of the complete pathology report and note any unfamiliar terms. The report may describe staining intensity, distribution or whether the finding supports a particular diagnosis.

The stain itself does not cause symptoms because it is performed in the laboratory. Contact your care team about new concerns from the biopsy procedure, such as increasing pain, fever, heavy bleeding or redness at the sample site. Seek urgent help for severe bleeding, fainting or breathing difficulty.

Ask what TRAP is being used to investigate, what the staining pattern shows, which other markers were tested, and whether the result changes the working diagnosis or treatment plan. Ask when the full report will be discussed and whether a specialist pathology review would help.