What should you know about fish immunohistochemistry?

Immunohistochemistry uses antibodies that attach to selected proteins in tissue, allowing a pathologist to see where those proteins are present and how strongly they appear. FISH, or fluorescence in situ hybridisation, uses labelled probes to look for particular gene changes or chromosome arrangements inside cells.

The tests may be used on tissue obtained through a biopsy. They can help classify a tumour, confirm its origin, or identify a feature that affects treatment choices. A result must be interpreted alongside the tissue appearance, clinical history, imaging, and other laboratory findings.

Ask which test was performed, what marker or gene change it examined, and whether the sample was adequate. Request an explanation of terms such as positive, negative, equivocal, or insufficient, because their meaning depends on the specific assay and threshold.

If the result is unclear, the laboratory may review the slide, repeat a test, or use another method. Keep the pathology report with your medical records and ask how the finding changes diagnosis, treatment options, or the need for additional testing.

FISH and immunohistochemistry themselves usually do not cause new symptoms because they are performed on a tissue sample already collected. Seek care for biopsy-related worsening pain, heavy bleeding, fever, increasing swelling, or drainage, and contact the oncology team when a result is confusing or a treatment decision is waiting on it.

What exactly was tested, and what does my result mean for the tumour diagnosis? Was the sample sufficient? Could another test change the interpretation, and how will this finding affect treatment planning?