When a Second Pathology Review Changes the Diagnosis

This page is for people thinking about a second pathology opinion, or whose second opinion came back different. It explains how often reviews change things, when they matter most, and how to arrange one.

At its foundation, a cancer diagnosis is one pathologist's reading of cells on a glass slide. Often that reading is clear. Sometimes it is harder, and another pathologist may see it differently. These calls can rest on small features of the cells.

Second-opinion pathology review means sending your existing slides, and sometimes the paraffin block, to a different pathologist. Ask your care team whether a new sample would be needed.

This page does not give a percentage, because we could not confirm one from a federal source. What NCI does say is that patients interested in a second opinion should talk with their doctor. Your doctor can tell you whether a second review could matter for your case.

A second review may be worth asking about where the diagnosis is hard to call, or where a wrong answer would have large effects. Ask your care team about cases like these:

• Rare tumors, especially sarcomas and unusual lymphomas.
• Any report that says it is unsure in its own wording, such as "suspicious for," "cannot exclude," or "favor."
• Thyroid nodule cytology (tests on cells taken with a needle).
• Borderline lesions of the breast, ovary, and skin, where the line between atypia (cells that look odd but may not be cancer) and malignancy (cancer) is genuinely contested.
• Any diagnosis leading to major surgery that cannot be undone, or removal of an organ.
• Any case where the pathology does not fit the clinical picture.

It helps to ask early, so the result can be used before treatment decisions are made.

Talk to your doctor first. NCI says patients interested in a second opinion should talk with their doctor. The material has to be physically obtained. NCI notes that you will need to get the slides, or the paraffin block, from the pathologist who examined the sample. You can also get them from the hospital where the biopsy or surgery was done.

NCI says many institutions provide second opinions on pathology specimens. NCI-designated cancer centers or academic institutions sometimes do. Contact the receiving institution in advance. Confirm that it offers the service, and ask about cost and shipping instructions.

Ask that the second report go to you and to your treating team.

This is unsettling. It does not necessarily mean either pathologist was careless. Some diagnoses are hard to call. Ask your care team what the next step is, and whether more testing could settle the question.

Ask which diagnosis your treatment is being based on, and why. Ask whether any further test could settle the disagreement. Ask what would change if the other diagnosis were correct. Sometimes both readings lead to the same treatment. That is reassuring, and it is worth establishing out loud. Sometimes they do not lead to the same treatment. Finding that out is exactly the point of having looked twice.

• NCI: Pathology Reports fact sheet (second opinion section)