fibromatosis

Meaning of fibromatosis: Growths that invade locally and return after removal yet never travel to distant organs, sitting between benign and malignant.

Definition of fibromatosis

Fibromatosis is a group of growths built from fibroblasts, the cells that lay down the fibrous scaffolding of tissue, which spread by infiltrating into whatever lies next to them. They are not cancers in the ordinary sense, since they do not seed distant organs, yet they invade locally and recur stubbornly after surgery. Familiar examples include the tethered fingers of Dupuytren contracture and desmoid tumors.

How is it different from a fibroma?

A fibroma is a discrete lump of fibrous tissue with a clean edge that can be shelled out whole. Fibromatosis has no edge at all. Strands of cells run out from the main mass into surrounding muscle, fat and connective tissue, so what looks like a boundary is only where the visible part stops. Describing the condition as one in which multiple fibromas develop therefore misses it twice over: the lesions are not fibromas, and what defines them is the way they infiltrate rather than how many there are.

Which forms are common?

FormWhere it appearsWhat is noticed
Dupuytren contracturePalm and fingersCords beneath the skin pull fingers toward the palm
Plantar fibromatosisSole of the footFirm nodules in the arch, sore under weight
Peyronie diseaseShaft of the penisCurvature and pain from a fibrous plaque
Desmoid tumorAbdominal wall, limbs, inside the abdomenA deep firm mass that enlarges and infiltrates

Why does it recur so readily?

Because the surgeon removes what can be seen and the growth extends into tissue that looks normal. Taking a generous margin lowers the recurrence rate without abolishing it, and around joints or major vessels a generous margin may not be possible. The deep forms behave most awkwardly, which is why a desmoid is classed as an intermediate growth rather than a benign tumor: locally aggressive, sometimes disabling, but incapable of metastasis, unlike a soft tissue sarcoma, which it can resemble under the microscope. Many desmoids also stop growing or shrink of their own accord, so periods of watchful observation now precede surgery in many cases rather than following it. Some arise at the site of an earlier operation or injury, and a proportion occur in people carrying an inherited bowel polyp syndrome.

Also known as

aggressive fibromatosisdesmoid-type fibromatosis

Used in a sentence

Histology reported a fibromatosis infiltrating the surrounding muscle.

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Good to know

These growths do not metastasize, so the harm they cause comes from local invasion and repeated recurrence rather than from spread, and their ill-defined edge is what makes complete removal so difficult.

Word origin

Where “fibromatosis” comes from

Fibromatosis joins the Latin fibra, meaning a fiber or thread, with the Greek ending -osis, marking a condition or process.

For learning, not diagnosis. This glossary provides general educational information and is not a substitute for advice from a qualified healthcare professional. If you may be experiencing a medical emergency, contact local emergency services.