Submucosal, intramural and subserosal fibroids

Fibroids are named by where they grow in the uterus. Submucosal fibroids grow just under the inner lining, intramural fibroids grow in the muscle wall, and subserosal fibroids grow just under the outer surface¹. Pedunculated fibroids hang on a stalk, inside or outside the uterus¹. Imaging reports use these words for each fibroid.

A plain-language definition from the ProcedurePath glossary.

Written and reviewed by Varun Danda, MD, interventional radiology resident physician · Last reviewed October 25, 2026

What the words mean

Mucosa means lining, mural means wall, and serosa means the outer covering. So submucosal means under the lining, intramural means inside the wall, and subserosal means under the outer covering. Some reports call an intramural fibroid myometrial, after the muscle layer (myometrium)¹.

Your report may also give a FIGO number, which splits these groups more finely. See FIGO fibroid types.

Why location matters

Common fibroid symptoms include heavy periods, pressure in the lower belly, and needing to urinate more often¹. Location, size and number all shape symptoms and which treatments fit. Ask your doctor where your fibroids are and what that means for your options.

Read more: What are fibroids?

Common question

What is a pedunculated fibroid?

It is a fibroid that grows on a stalk, either inside the uterus or on its outer surface¹.

Talk with your doctor before you decide. This information does not replace personal medical advice. Read the medical disclaimer.

Sources

MedlinePlus Medical Encyclopedia, uterine fibroids ↩︎