Understanding the Difference Between Fibroids and Adenomyosis
You had an ultrasound, and the doctor told you that there is a lump in your uterus. Be sure to discuss with your doctor whether this lump is a fibroid or an adenomyosis lump, as this will determine whether you need surgery or not. So, make sure to read this blog till the end, because it will help you understand what exactly the difference is between fibroids and adenomyosis and how their treatments are different.
Hello, I am Dr. Amita Shah, Senior Consultant Gynecologist and Laparoscopic Surgeon, with expertise in Laparoscopic Robotic Surgery, practicing in Gurgaon.
What is a Fibroid?
A fibroid is a type of tumor or lump that grows from the surface inside your uterus, known as the myometrium. These fibroids can be single or multiple. If they grow towards the outside of the uterus, they are called subserosal fibroids. If they grow towards the inside of the uterus cavity, they are called submucosal fibroids. If they grow within the wall of the uterus, they are known as intramural fibroids.
What is Adenomyosis Uterus?
On the other hand, adenomyosis is a condition that affects the middle layer of the uterus, known as the myometrium. In this condition, the endometrium (the inner lining of the uterus) starts to grow into the myometrium. The cells of the endometrium gradually begin to invade the myometrium. Every time you have a period, these endometrial cells bleed, but since there’s no outlet for the blood within the myometrium (unlike the endometrium, which sheds blood during menstruation), the blood accumulates inside the myometrium.
If the blood accumulates throughout the myometrium, the myometrium becomes thickened, and the uterus becomes enlarged, which is called diffuse adenomyosis. If the blood collects in a localized area, it’s referred to as localized adenomyosis or adenomyoma. Adenomyoma is a lump formed from adenomyosis, and it is not a well-defined lump like a fibroid.
Symptoms of Fibroids and Adenomyosis
The symptoms of fibroids and adenomyosis are almost the same, such as:
- Severe pain during periods
- Irregular cycles
- Heavy flow during periods
- Passage of clots during periods
- Painful intercourse
- Infertility
However, the key difference is that adenomyosis typically presents with severe pain during periods as the predominant symptom.
How Ultrasound Helps Diagnose Fibroids and Adenomyosis?
To diagnose this, an ultrasound is usually enough. A good ultrasound test can help us tell the difference between fibroids and adenomyosis. A fibroid shows up as a clear, well-defined lump, while an adenomyosis lump is not clearly defined. It appears as a spread-out lump in the uterine wall (myometrium).
Treatment Options: Fibroid Surgery vs. Adenomyosis Medication
So, how is the treatment different?
If you have a fibroid that is very large and symptomatic, we may need to remove it surgically. However, if it’s adenomyosis, and if we diagnose it in time, we can treat it with medication.
What medications are used?
These include things like contraceptive pills, Diane-35 (which is a progestogen-only pill), or Mirena, which is a device similar to an IUD that releases progestin.
Medications Treatment for Adenomyosis
Medicine treatment for adenomyosis gradually causes the lining of the uterus to dry up, and the endometrial cells inside the myometrium also shrink. In 70-80% of cases, we can treat adenomyosis with just medications. So, if you have been told that you have a lump in your uterus, make sure to discuss whether it is a fibroid or adenomyosis because your treatment will depend on that diagnosis.
Adenomyosis Vs Fibroids – Differences
| Feature | Adenomyosis | Fibroids |
| Definition | Endometrial tissue grows into the uterine muscle. | Benign tumors that grow in or around the uterus. |
| Location | Inner lining grows within the uterine muscle. | Develops on the outer surface, within the wall, or inside the uterine cavity. |
| Shape | Diffuse, less well-defined lump or thickening in the uterine wall. | Well-defined, solid lumps or masses. |
| Uterine Size | Uterus becomes uniformly enlarged and thickened. | Uterus may be enlarged depending on the size of the fibroids. |
| Symptoms | – Severe pain during periods – Heavy menstrual bleeding – Painful intercourse – Enlarged uterus | – Heavy menstrual bleeding – Irregular periods – Pressure or pelvic pain – Possible infertility |
| Common Age Group | Most common in women 40-50 years, particularly those who have had children. | Can affect women of any age, but more common in women 30-40 years. |
| Diagnosis | Typically diagnosed via ultrasound or MRI (less defined on ultrasound). | Diagnosed through ultrasound (clearly defined lumps). |
| Treatment | Hormonal treatments (e.g., birth control, IUD), pain management, hysterectomy (in severe cases). | Surgery (e.g., myomectomy), medications (e.g., GnRH agonists), or hysterectomy in severe cases. |
| Cause | Likely hormonal and related to uterine trauma (e.g., previous surgeries). | The exact cause is unknown but may be linked to hormonal imbalances (e.g., estrogen). |
| Impact on Fertility | Can cause infertility, though treatable in many cases. | Can cause infertility if fibroids block the fallopian tubes or affect implantation. |
