Benign

A benign growth grows slowly, keeps a clear boundary, often sits inside a capsule, and looks under the microscope much like the tissue it came from. It has no capacity to seed itself elsewhere, which is the single feature that separates it from something malignantMalignantMalignant describes a growth that can invade the tissue around it and spread to other parts of the body. It is the opposite of benign, which stays where it started.Read the full definition. Most lumps a person finds are benign — the fatty lipoma, the fibroadenoma of the breast, the thyroid nodule, the uterine fibroid, the skin tag, the ordinary mole.

Benign is not the same as harmless

A benign tumour can still cause serious trouble by pressing on something, by bleeding, or by producing a hormone. A benign meningioma inside the skull has nowhere to expand into. Fibroids can cause enough monthly blood loss to produce anaemiaAnaemiaAnaemia means the blood carries less haemoglobin than it should, so less oxygen reaches the tissues. It usually shows itself as tiredness, breathlessness on exertion and pallor, and in Pakistan the commonest cause by a wide margin is a shortage of iron.Read the full definition. A benign adenoma of the pituitary may flood the body with a hormone it does not need. So benign answers one question — will this spread — and leaves the question of whether it needs treating entirely open.

The word carries real weight on a pathology report, and it is worth knowing how it was reached. Imaging and examination can suggest benign; only a biopsyBiopsyA biopsy is the removal of a small piece of tissue so that it can be examined under a microscope. It is the test that settles what a lump, an ulcer or an abnormal patch actually is, when scans and blood tests can only suggest.Read the full definition and a pathologist looking at the cells can say it. Two cautions belong with the word. A benign result applies to the tissue that was sampled, so a report that does not match the clinical picture is repeated rather than trusted. And a few benign lesions carry a small chance of change over years, which is why some are watched with a scan or an examination at intervals rather than simply forgotten.