Uterine fibroids are often confused with the following conditions, and careful differentiation is necessary.
1. Pregnancy
Cystic degeneration of fibroids may lead to a misdiagnosis of pregnancy. Conversely, a pregnant uterus — especially in women over 40 or in cases of missed abortion with bleeding — may be misdiagnosed as fibroids. For women of childbearing age with amenorrhea, pregnancy should always be considered first. Diagnosis can be confirmed easily with ultrasound or hCG testing; if needed, dilation and curettage may help distinguish the two. Special attention should be paid to fibroids combined with pregnancy, in which the uterus is larger than expected for gestational age, irregular in shape, and firm on palpation. Ultrasound is highly helpful in such cases.
2. Ovarian Tumors
Solid ovarian tumors may be mistaken for subserosal fibroids. Similarly, cystic degeneration of subserosal fibroids is often misdiagnosed as ovarian cysts. Differentiation becomes even more difficult when ovarian tumors are adherent to the uterus. Ultrasound can assist evaluation, and in some cases, final diagnosis can only be made during laparotomy.
3. Adenomyosis
Adenomyosis also causes heavy menstrual bleeding and uterine enlargement. The key difference from fibroids is severe dysmenorrhea, although some cases show minimal pain and are misdiagnosed as fibroids. On examination, the uterus is usually symmetrically enlarged and characteristically increases in size during menstruation and decreases afterward.
4. Uterine Hypertrophy
This condition also presents with menorrhagia and an enlarged uterus, making it easily confused with fibroids. However, uterine hypertrophy involves uniform enlargement, rarely exceeding the size of a 2‑month pregnancy. Ultrasound helps establish the correct diagnosis.