Reactive changes

Reactive changes is a commonly used term in pathology that implies:

Inflammation.
Nuclear changes compatible with inflammation.
The absence of both neoplasia and the suspicious of neoplasia, i.e. it implies benignancy.

Reactive inflammatory changes and inflammatory changes can be considered synonyms.

General

Nuclear changes are seen in:

Inflammatory processes.
Repair.
Neoplastic processes, i.e. pre-cancerous conditions (e.g. dysplasia) and cancer.

Significance of nuclear changes in inflammation:

The line between a reactive process and a neoplastic process may be fuzzy, i.e. it may be very difficult to be certain whether something is benign or malignant.

Consequence:

In the context of inflammation, nuclear changes are typically present and the threshold for calling suspicious for malignancy or malignancy is typically higher.

Features - generic:

Nuclear changes - typically:
- Nuclear enlargement.
- Nuclear hyperchromasia.
- Prominent nucleoli.
Inflammation - any type (e.g. neutrophilic, plasmacytic, lymphoplasmacytic).
+/-Proliferation (e.g. mitotic figures) or changes suggestive of proliferation (e.g. hyperplasia).

DDx:

Normal.
Waffle diagnosis - nuclear changes of unknown significance.
- Terminology dependent on the anatomical site, e.g. indefinite for dysplasia, ASCUS, ASAP.
Nuclear atypia.
- This is often qualified as it may represent a neoplastic process or a benign process.
- Common qualifiers:
  - Worrisome lesions: "... cannot exclude dysplasia", "... cannot exclude malignancy", "... suspicious for malignancy".
  - Suspected to be benign: "... favour benign".
Malignancy.