When the Margins Are “Clean But Close” After Tumor Removal

A middle category between “clean” and “incomplete” margins helps with a prognosis.

Published: May 22, 2023

p3_bigstock-Sick-Domestic-Cat-Lies-After-S-455246185 — © blinova_ti | Bigstock Once the tumor is removed and the cat is resting comfortably, samples of the excised mass will be checked to see if there are clean margins, as well as whether the tumor is malignant (likely to spread).

When a veterinarian removes a possible malignant tumor, she also removes a cuff of surrounding normal-appearing tissue to improve the chances that the tumor will not grow back. A pathologist then looks at the perimeter (or “margins”) of the resected tumor under a microscope to see whether it appears to have been fully removed. The margins are categorized as complete (no residual cancer seen) or incomplete (residual cancer seen).