Fibroid types
Reading File
Finding Sources
Finding Sources
Reading File
Reading File
Finding Sources
Loading Image
Reading File
Here is a complete breakdown of fibroid (leiomyoma) types, drawn from Berek & Novak's Gynecology:
Uterine Fibroid (Leiomyoma) Types
FIGO Classification System
The most widely used system classifies fibroids by their relationship to the uterine wall layers. There are 9 types (0-8):
Submucosal (SM) - Types 0, 1, 2
These grow toward or into the uterine cavity and most commonly cause heavy bleeding and infertility.
| Type | Name | Description |
|---|---|---|
| 0 | Pedunculated intracavitary | Entirely within the uterine cavity, attached by a stalk |
| 1 | Submucosal | <50% of the fibroid diameter within the myometrium |
| 2 | Submucosal | ≥50% of the fibroid diameter within the myometrium |
"Other" / Intramural & Subserosal (O) - Types 3-7
These are designated under the "Other" category in FIGO.
| Type | Name | Description |
|---|---|---|
| 3 | Intramural (endometrium-abutting) | Contacts the endometrium; 100% within the myometrium, no intracavitary component |
| 4 | Intramural | Entirely within the myometrium; no extension to endometrial surface or serosa |
| 5 | Subserosal | ≥50% intramural (mostly within the wall) |
| 6 | Subserosal | <50% intramural (mostly projecting outward) |
| 7 | Pedunculated subserosal | Attached to the serosa by a stalk; projects outside the uterus |
Special / Other - Type 8
| Type | Description |
|---|---|
| 8 | No myometrial involvement - includes cervical fibroids, round/broad ligament fibroids without direct uterine attachment, and parasitic fibroids (have developed their own blood supply from other structures) |
Hybrid (Transmural) Fibroids
Fibroids that span both the endometrial and serosal surfaces are described using two numbers separated by a hyphen. By convention, the first number refers to the relationship with the endometrium, the second to the serosa.
- Example: Type 2-5 = submucosal with <50% in the cavity AND subserosal with <50% protruding externally (the fibroid spans the full thickness of the myometrium)
Histologic Variants (WHO Classification)
Beyond location, fibroids are also categorized by microscopic features:
| Variant | Key Feature |
|---|---|
| Mitotically active leiomyoma | 10-15 mitoses/10 hpf; often seen in pregnancy or with exogenous hormone use |
| Cellular leiomyoma | Higher cellularity than adjacent myometrium; ~2% recurrence rate |
| Leiomyoma with bizarre nuclei (atypical/symplastic) | Scattered large atypical cells; ~12% recurrence after hysterectomy |
| STUMP (Smooth muscle tumor of uncertain malignant potential) | Atypical features between leiomyoma and LMS; ~7% recurrence; rare malignant transformation |
| Leiomyosarcoma (LMS) | Malignant; hypercellularity, diffuse atypia, ≥10 mitoses/hpf, tumor necrosis; prevalence ~1 in 1,429 fibroid surgeries |
Clinical Correlation by Location
- Submucosal (Types 0-2): Most likely to cause heavy menstrual bleeding, iron-deficiency anemia, and subfertility. Best visualized with saline-infusion sonography (SIS), hysteroscopy, or MRI.
- Intramural (Types 3-4): Can enlarge the uterus and cause bulk symptoms (pressure, urinary frequency, constipation).
- Subserosal (Types 5-7): Often cause pelvic pressure or pain; pedunculated forms (Type 7) can tort on their stalk.
- Type 8 / Parasitic: Can be found in the broad ligament or other pelvic structures; may be a complication of previous laparoscopic morcellation.
- Berek & Novak's Gynecology, pp. 506-508
Give from shaw textbook
Finding Sources
Finding Sources
Finding Sources
Unfortunately, Shaw's Textbook of Gynaecology is not available in the medical library. The only gynaecology/obstetrics textbooks in the library are:
- Berek & Novak's Gynecology (which I used in the previous answer)
- Creasy & Resnik's Maternal-Fetal Medicine (focused on obstetrics/high-risk pregnancy)
Shaw's is not present in the collection. I can offer you the fibroid types as described in Shaw's from my training knowledge, if that would help - just let me know. Or if you have a PDF/image of the relevant Shaw's chapter, you can attach it and I'll extract the content for you.
Do you have Shaw's textbook chapter to upload?
No, I don't have the ability to upload or share files to you - I can only receive files that you upload to me.
Here's what you can do:
-
You upload it - If you have Shaw's Textbook of Gynaecology (PDF or image of the fibroid chapter), attach it to your next message and I'll extract and explain all the content for you.
-
I answer from memory - I have training knowledge of Shaw's classification of fibroids and can summarize it for you right now, clearly labeled as being from training data (not a live textbook read). Just say "yes, go ahead."
Which would you prefer?
Yes
Here is the classification of fibroids as described in Shaw's Textbook of Gynaecology (from training knowledge):
Fibroid Types - Shaw's Textbook of Gynaecology
Classification by Site
1. Intramural (Interstitial) - Most Common
- Located within the myometrium
- Surrounded by a capsule of compressed muscle fibres
- Causes uniform enlargement of the uterus
- May become submucosal or subserosal as they grow
- Symptoms: menorrhagia, pelvic heaviness
2. Submucosal - Most Symptomatic
- Lies just beneath the endometrium, projecting into the uterine cavity
- Even a small submucosal fibroid causes heavy menstrual bleeding
- Associated with infertility and recurrent miscarriage
- Can become pedunculated and prolapse through the cervix (fibroid polyp)
- May undergo red degeneration during pregnancy
3. Subserosal (Subperitoneal)
- Lies just beneath the peritoneal (serosal) surface of the uterus
- Projects outward from the uterine surface
- May become pedunculated - attached by a pedicle/stalk
- A pedunculated subserosal fibroid can:
- Tort (twist on its pedicle) causing acute pain
- Become parasitic - detaches and derives blood supply from omentum or other structures
- Least likely to cause bleeding
4. Cervical Fibroid
- Arises from the cervical musculature (rarer, ~2% of fibroids)
- Situated below the internal os
- Can be anterior, posterior, lateral or central
- Causes:
- Urinary retention (anterior cervical fibroid compresses bladder/urethra)
- Difficulty in delivery
- Dyspareunia
- Complicates myomectomy significantly
5. Broad Ligament (Intraligamentary) Fibroid
- Develops in the leaves of the broad ligament
- Usually subserosal in origin, expanding laterally
- Displaces the ureter, uterine vessels, and bladder
- Risk of ureteric injury during surgery is high
- Can mimic an ovarian mass clinically
6. Parasitic Fibroid
- A pedunculated fibroid that has detached from the uterus and acquired a new blood supply (omentum, bowel, bladder)
- Rare but important to recognize surgically
Degenerations of Fibroid (Shaw's also covers these)
| Type | Feature |
|---|---|
| Hyaline | Most common; collagen replaces muscle - fibroid becomes firm/white |
| Cystic | Hyaline tissue liquefies into cystic spaces |
| Red (Carneous) | Seen in pregnancy; aseptic infarction - painful; cut surface is red/raw |
| Calcific | Calcium deposited; "womb stone"; postmenopausal |
| Fatty (Lipomatous) | Fat deposited; rare |
| Sarcomatous | Malignant change; rare (~0.1-0.5%); rapid enlargement after menopause is a warning sign |
Note: This is based on my training knowledge of Shaw's Textbook of Gynaecology and should be verified against your edition. If you can upload the actual chapter, I can give you the exact text, page numbers, and any diagrams.
This is a shared conversation. Sign in to Orris to start your own chat.