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PubMed This is a summary of 23 peer-reviewed journal articles Updated
Gynecology · Uterine Fibroids

Does Rapid Fibroid Growth Mean Uterine Cancer? Signs to Know

At a Glance

Rapid growth of a uterine fibroid does not by itself mean cancer because benign fibroids can grow quickly. Doctors consider age, symptoms, imaging, and biopsy, but only examination of the removed mass may definitively distinguish a fibroid from the rare uterine sarcoma.

In this answer

4 sections

01

Benign Fibroids Can Grow Quickly

02

When Might Doctors Investigate Further?

03

How Doctors Evaluate a Suspicious Mass

04

What This Means for Surgery

It is incredibly frightening to be told that a tumor is growing quickly, but rapid growth of a uterine fibroid is not, by itself, a definitive sign of cancer [1]. Benign (non-cancerous) fibroids can grow very quickly [2]. Because a rare type of uterine cancer called a uterine sarcoma can also grow rapidly, doctors evaluate growth alongside your age, symptoms, and imaging [3][1]. Studies of patients having surgery for presumed fibroids show that the overall risk of finding an unexpected sarcoma is very low, ranging from roughly 0.04% to 0.33% [4][5]. Your individual risk depends on your specific clinical picture, not just on a single growth measurement.

Benign Fibroids Can Grow Quickly

It is a common misconception that only cancerous tumors grow fast. Research shows that typical, benign fibroids (also called leiomyomas) can undergo substantial growth spurts [2][6]. Small fibroids can sometimes grow at faster rates than larger ones, and a fibroid’s size naturally fluctuates over time [2].

Apparent “rapid growth” can also sometimes be the result of differences in how ultrasound or MRI measurements were taken, or a benign process where the fibroid outgrows its blood supply [7][8]. Because rapid growth is frequently seen in completely benign masses, growth rate alone cannot diagnose cancer [1][9].

When Might Doctors Investigate Further?

While growth speed alone is not a reliable test for cancer, the context of that growth helps your care team decide if further investigation is needed. None of the following signs proves you have cancer, but they are important patterns doctors look for:

  • Growth after menopause: Fibroids are fueled by hormones and typically stop growing or shrink after a person goes through menopause [10]. A newly enlarging uterine mass after menopause is an important sign that warrants timely specialist assessment, though it still does not guarantee cancer [10][11].
  • Abnormal bleeding: Postmenopausal bleeding, or newly worsening heavy bleeding, should always be thoroughly evaluated [11][12]. While these symptoms have many benign causes (like ordinary fibroids or changes in the uterine lining), they also require investigation to rule out a malignancy [12]. (Note: If bleeding is extremely heavy or accompanied by faintness, seek prompt medical care).
  • A solitary mass: Having a single rapidly growing mass is one pattern doctors consider alongside other factors [11]. However, most solitary masses are still benign fibroids, and this alone is not a reliable way to distinguish between the two [11].
  • Severe pain or pressure: New or unexplained pelvic pain and pressure warrant assessment [13]. These symptoms are extremely common with benign fibroids, but doctors will look at them as part of your overall health picture [12].

How Doctors Evaluate a Suspicious Mass

Advanced Imaging

An ultrasound is usually the first step, but a pelvic MRI (magnetic resonance imaging) is often the most useful tool for evaluating a suspicious uterine mass [14][15]. Radiologists look for specific warning features like irregular borders or necrosis (areas of dead tissue) [14][16].

However, imaging cannot definitively prove or disprove cancer [7][17]. A benign fibroid undergoing degeneration (dying tissue) can look remarkably similar to a sarcoma on both an ultrasound and an MRI [8][7].

Tissue Sampling and Definitive Diagnosis

Your doctor may recommend an endometrial biopsy, a quick procedure to sample the lining of the uterus [18]. While this can detect a cancer that has reached the uterine cavity, it has limited ability (low sensitivity) to detect a sarcoma buried deep within the muscular wall of the uterus [19][20].

Because of this, a “clear” biopsy does not entirely rule out cancer if imaging or symptoms remain highly suspicious [18][20]. Ultimately, a definitive diagnosis of a suspected sarcoma often requires examining the entire mass under a microscope after it is surgically removed [19][10].

What This Means for Surgery

If your medical team highly suspects that a mass could be a sarcoma based on your age, imaging, and symptoms, it changes how surgery should be approached [20][21].

A major surgical precaution is avoiding uncontained morcellation. Morcellation is a technique where a surgeon cuts a large mass into smaller pieces to remove it through tiny incisions [22]. If an unexpected cancer is fragmented without being contained in a surgical bag, it can spread cancerous tissue throughout the abdomen [22][23].

When there is a strong suspicion of sarcoma, doctors generally recommend the mass be removed intact (en bloc) [20]. This may require a different surgical route, such as a larger abdominal incision. If a minimally invasive route is chosen for a presumed fibroid, you and your surgeon can discuss whether contained morcellation (using a specialized bag) is appropriate and safe for your specific situation [20].

If the combined clinical picture raises high concern for cancer, it is recommended that you be evaluated by a gynecologic oncologist (a specialist in female reproductive cancers) to help plan the safest surgical approach [21].

Common questions in this guide

Does rapid growth of a uterine fibroid mean it is cancer?
No. Benign fibroids can grow quickly, and a growth rate alone cannot distinguish a fibroid from cancer. Because a rare uterine cancer called sarcoma can also grow rapidly, doctors consider your age, symptoms, and imaging together.
Why is a fibroid that grows after menopause more concerning?
Fibroids are usually supported by hormones and often stop growing or shrink after menopause. A new or enlarging uterine mass after menopause therefore deserves timely medical assessment, although it still does not prove cancer. Other causes remain possible.
Can an MRI tell whether a rapidly growing fibroid is cancer?
MRI is often the most useful imaging test for examining a suspicious uterine mass and may show features such as irregular borders or dead tissue. However, benign fibroid changes can look like cancer on MRI, so imaging cannot provide certainty by itself.
Will a normal endometrial biopsy rule out uterine sarcoma?
Not always. An endometrial biopsy samples the lining of the uterus and may miss a sarcoma located deep in the muscular wall. If symptoms or imaging remain concerning, doctors may need additional evaluation, and examination of a surgically removed mass may be needed for a definitive diagnosis.
What symptoms should I report with a rapidly growing fibroid?
Report new or worsening heavy bleeding, bleeding after menopause, pelvic pain, or pressure to your clinician. These symptoms often have benign causes, but they should be evaluated in context. Seek prompt medical care if bleeding is extremely heavy or causes faintness.
Why does morcellation matter if cancer is suspected?
Morcellation breaks a mass into smaller pieces for removal through small incisions. If the mass contains an unexpected cancer and the pieces are not contained, cancerous tissue could spread through the abdomen. When suspicion is high, doctors may recommend removing the mass intact and involving a gynecologic oncologist.

Questions For You

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Related questions

What Do Hybrid FIGO 2-5, 3-5, or 2-6 Uterine Fibroids Mean? When is Heavy Bleeding from Uterine Fibroids an Emergency? When Should I Have MRI, SIS, or Hysteroscopy for Fibroids? Can Uterine Fibroids Cause Fatigue and Shortness of Breath? When Is Severe Uterine Fibroid Pain or Fever an Emergency?
Show more
Can Uterine Fibroids Cause Painful Sex or Sexual Changes? Can Fibroids Cause Abdominal Enlargement or Weight Gain? Do I Need an Endometrial Biopsy for Fibroid Bleeding? How Is Postmenopausal Bleeding Evaluated With Fibroids? How Are Cavity-Distorting Fibroids Treated Before IVF? What Blood Tests Are Needed for Anemia From Fibroids? Do Uterine Fibroids Become Cancerous or Raise Cancer Risk? Can Fibroids Cause Constipation, Bloating or Urinary Issues? Can Asymptomatic Uterine Fibroids Be Safely Left Untreated? Do Uterine Fibroids Run in Families? Screening Advice Do Uterine Fibroids Shrink Before or After Menopause? Can Diet, Exercise, or Supplements Shrink Fibroids? How Are Fibroids Distinguished from Other Pelvic Conditions? Why Are Fibroids More Common and Severe in Black Women?

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Questions to Ask Your Doctor

Curated prompts to bring to your next appointment.

  1. 1.Were my recent imaging scans compared side-by-side using the same measurement method, and how reliable is the reported growth?
  2. 2.Based on my age, symptoms, and the imaging, what is your level of concern for something other than a typical fibroid?
  3. 3.What would an MRI or an endometrial biopsy add to our understanding of my specific mass?
  4. 4.If we proceed with surgery, what is the plan for removing the tissue, and will you use any form of uncontained or contained morcellation?
  5. 5.Do the features of my mass warrant a consultation with a gynecologic oncologist before we finalize a surgical plan?

References

References (23)
  1. 1

    ACOG Committee Opinion No. 770: Uterine Morcellation for Presumed Leiomyomas.

    Obstetrics and gynecology 2019; (133(3)):e238-e248 doi:10.1097/AOG.0000000000003126.

    PMID: 30801477
  2. 2

    Uterine fibroid incidence and growth in an ultrasound-based, prospective study of young African Americans.

    Baird DD, Patchel SA, Saldana TM, et al.

    American journal of obstetrics and gynecology 2020; (223(3)):402.e1-402.e18 doi:10.1016/j.ajog.2020.02.016.

    PMID: 32105679
  3. 3

    Proportion of Uterine Malignant Tumors in Patients with Laparoscopic Myomectomy: A National Multicenter Study in China.

    Yang H, Li XC, Yao C, et al.

    Chinese medical journal 2017; (130(22)):2661-2665 doi:10.4103/0366-6999.218008.

    PMID: 29133752
  4. 4

    Risk of unexpected uterine leiomyosarcoma during laparoscopic procedures: Experience from a single tertiary institute in Italy.

    Surace A, Baù MG, Privitera S, et al.

    International journal of gynaecology and obstetrics: the official organ of the International Federation of Gynaecology and Obstetrics 2022; (156(2)):236-239 doi:10.1002/ijgo.13701.

    PMID: 33834486
  5. 5

    Frequency of uterine sarcomas in patients admitted for uterine fibroid surgery.

    Mettler L, Maass N, Abdusattarova K, et al.

    Journal of the Turkish German Gynecological Association 2017; (18(2)):62-66 doi:10.4274/jtgga.2016.0248.

    PMID: 28400352
  6. 6

    Natural History of Uterine Fibroids: A Radiological Perspective.

    Ghosh S, Naftalin J, Imrie R, Hoo WL

    Current obstetrics and gynecology reports 2018; (7(3)):117-121 doi:10.1007/s13669-018-0243-5.

    PMID: 30101039
  7. 7

    Smooth Muscle Tumors of the Uterus at MRI: Focus on Leiomyomas and FIGO Classification.

    Tu W, Yano M, Schieda N, et al.

    Radiographics : a review publication of the Radiological Society of North America, Inc 2023; (43(6)):e220161 doi:10.1148/rg.220161.

    PMID: 37261965
  8. 8

    Comparison of the diagnostic accuracy of contrast-enhanced MRI and diffusion-weighted MRI in the differentiation between uterine leiomyosarcoma / smooth muscle tumor with uncertain malignant potential and benign leiomyoma.

    Lin G, Yang LY, Huang YT, et al.

    Journal of magnetic resonance imaging : JMRI 2016; (43(2)):333-42 doi:10.1002/jmri.24998.

    PMID: 26383110
  9. 9

    Clinical Characteristics Differentiating Uterine Sarcoma and Fibroids.

    Chen I, Firth B, Hopkins L, et al.

    JSLS : Journal of the Society of Laparoendoscopic Surgeons 2018; (22(1)) doi:10.4293/JSLS.2017.00066.

    PMID: 29398899
  10. 10

    Leiomyoma with KAT6B-KANSL1 fusion: case report of a rapidly enlarging uterine mass in a postmenopausal woman.

    Ainsworth AJ, Dashti NK, Mounajjed T, et al.

    Diagnostic pathology 2019; (14(1)):32 doi:10.1186/s13000-019-0809-1.

    PMID: 31027501
  11. 11

    Preoperative clinical characteristics between uterine sarcoma and leiomyoma in patients with uterine mass, a case-control study.

    Chantasartrassamee P, Kongsawatvorakul C, Rermluk N, et al.

    European journal of obstetrics, gynecology, and reproductive biology 2022; (270()):176-180 doi:10.1016/j.ejogrb.2022.01.013.

    PMID: 35074691
  12. 12

    Diagnosis of Leiomyosarcoma after Uterine Artery Embolization for Multiple Leiomyomas.

    Tsuji M, Kihara T, Hushimi S, et al.

    Case reports in obstetrics and gynecology 2020; (2020()):8823428 doi:10.1155/2020/8823428.

    PMID: 33204553
  13. 13

    Exploratory Preoperative Risk Stratification of Uterine Mesenchymal Tumors in Postmenopausal Women with Complementary Transcriptomic Analysis.

    Wan X, Zhang T, Li J, et al.

    Diagnostics (Basel, Switzerland) 2026; (16(15)) doi:10.3390/diagnostics16152409.

    PMID: 42587646
  14. 14

    Validating the diagnostic accuracy of an MRI-based scoring system for differentiating benign uterine leiomyomas from leiomyosarcomas.

    Al Khuri M, Al Salmi I, Al Ajmi H, et al.

    International journal of gynecological cancer : official journal of the International Gynecological Cancer Society 2024; (34(7)):1027-1033.

    PMID: 38658016
  15. 15

    Imaging in gynecological disease (15): clinical and ultrasound characteristics of uterine sarcoma.

    Ludovisi M, Moro F, Pasciuto T, et al.

    Ultrasound in obstetrics & gynecology : the official journal of the International Society of Ultrasound in Obstetrics and Gynecology 2019; (54(5)):676-687 doi:10.1002/uog.20270.

    PMID: 30908820
  16. 16

    Ultrasound Features of Uterine Sarcomas.

    Oh J, Park SB, Park HJ, Lee ES

    Ultrasound quarterly 2019; (35(4)):376-384 doi:10.1097/RUQ.0000000000000454.

    PMID: 31094892
  17. 17

    PREOPERATIVE MAGNETIC RESONANCE IMAGING DIAGNOSTIC FEATURES OF UTERINE LEIOMYOSARCOMAS: A SYSTEMATIC REVIEW.

    Kaganov H, Ades A, Fraser DS

    International journal of technology assessment in health care 2018; (34(2)):172-179 doi:10.1017/S0266462318000168.

    PMID: 29642961
  18. 18

    The Role of Endometrial Biopsy in the Preoperative Detection of Uterine Leiomyosarcoma.

    Hinchcliff EM, Esselen KM, Watkins JC, et al.

    Journal of minimally invasive gynecology 2016; (23(4)):567-72.

    PMID: 26851414
  19. 19

    Results of Endometrial Biopsy and Its Impact on Survival Data in Patients with High-Risk Uterine Sarcoma.

    Alwafai Z, Reichert VMC, Spring P, et al.

    Journal of clinical medicine 2024; (13(14)) doi:10.3390/jcm13144048.

    PMID: 39064089
  20. 20

    European Society of Gynecological Oncology Statement on Fibroid and Uterine Morcellation.

    Halaska MJ, Haidopoulos D, Guyon F, et al.

    International journal of gynecological cancer : official journal of the International Gynecological Cancer Society 2017; (27(1)):189-192 doi:10.1097/IGC.0000000000000911.

    PMID: 28002210
  21. 21

    Impact of guideline adherence and expert center referral on the early management and outcomes of uterine sarcoma patients: A retrospective analysis from the French NETSARC network.

    Richaud C, Jochum F, Journo G, et al.

    European journal of surgical oncology : the journal of the European Society of Surgical Oncology and the British Association of Surgical Oncology 2024; (50(2)):107319 doi:10.1016/j.ejso.2023.107319.

    PMID: 38159391
  22. 22

    No. 371-Morcellation During Gynaecologic Surgery: Its Uses, Complications, and Risks of Unsuspected Malignancy.

    Murji A, Scott S, Singh SS, et al.

    Journal of obstetrics and gynaecology Canada : JOGC = Journal d'obstetrique et gynecologie du Canada : JOGC 2019; (41(1)):116-126 doi:10.1016/j.jogc.2018.07.016.

    PMID: 30580824
  23. 23

    Association Between Power Morcellation and Mortality in Women With Unexpected Uterine Cancer Undergoing Hysterectomy or Myomectomy.

    Xu X, Lin H, Wright JD, et al.

    Journal of clinical oncology : official journal of the American Society of Clinical Oncology 2019; (37(35)):3412-3424 doi:10.1200/JCO.19.00562.

    PMID: 31518176

This page is for informational purposes only and does not constitute medical advice about a rapidly growing fibroid. Your gynecologist or gynecologic oncologist can interpret your imaging, symptoms, and surgical options.