Addendum

An addendum is an additional note or update that is added to a pathology report after the original report has been issued. It allows the pathologist to provide new information or to clarify the findings already described. The addendum becomes a permanent part of your pathology report and should always be read together with the original document.

Why would an addendum be added?

There are several reasons why a pathologist may add an addendum to a pathology report:

• New test results: Occasionally, additional tests, such as immunohistochemistry or molecular tests, are ordered after the original report is signed out. Once these results are available, they are added in an addendum.

• Greater clarity: Occasionally, a pathologist may want to expand on their original explanation to make sure the meaning is clear to the doctors using the report.

• Additional clinical information: If new relevant information is provided by the treating team after the initial report, it may be documented in an addendum to give better context.

An addendum should not be used to fix errors or correct the original diagnosis. If a correction or significant change is needed, the pathologist issues an amended report, not an addendum.

Where is the addendum found in the report?

The addendum is usually placed in a clearly marked section of the pathology report. Depending on the laboratory or hospital system, it may appear at the top of the report, before the original findings, or at the end of the report, after the original text. In either case, the report will be clearly labeled to show which parts are from the original report and which are from the addendum. Both should always be read together.

Why is an addendum important?

An addendum is important because it ensures your pathology report includes the most complete information available. This may include results from specialized tests or explanations that help guide your doctor’s treatment decisions. Even if the main diagnosis does not change, an addendum can provide key details that affect follow-up or therapy.

How is an addendum different from an amendment?

An addendum provides new or clarifying information but does not change the original findings. An amendment is issued if there is a correction or significant change in the diagnosis or results.

Questions to ask your doctor

• Why was an addendum added to my pathology report?

• Does the addendum provide new information that changes my treatment plan?

• Were additional tests performed, and what did they show?

• Should I keep both the original report and the addendum in my medical records?