Diagnostic Approach for Women with Fibroids and Left-Sided Back Pain

First-Line Imaging

The American College of Radiology recommends pelvic ultrasound combining both transabdominal and transvaginal approaches with Doppler as the initial diagnostic method, with 90-99% sensitivity and 98% specificity for detecting uterine fibroids 2
This imaging helps determine fibroid location, size, and number, which is essential for understanding if the fibroids could be causing the back pain, according to the American College of Radiology 1, 2
Ultrasound can also help rule out other potential causes of left-sided back pain, such as renal pathology, which may present similarly, as suggested by the Journal of the American College of Radiology 3

MRI provides superior delineation of fibroid location, size, and number compared to ultrasound and can differentiate fibroids from adenomyosis and endometriosis, as recommended by the American College of Radiology 1, 2
MRI is particularly useful when multiple fibroids are present or when the relationship between fibroids and surrounding structures needs to be better understood, according to the American College of Radiology 2
Saline infusion sonohysterography (SIS) should be considered if submucosal fibroids are suspected, as it improves visualization between endometrial pathologies and submucosal fibroids, as suggested by the American College of Radiology 2

A complete blood count is recommended to assess for anemia, which may result from heavy menstrual bleeding associated with fibroids, according to the American Journal of Obstetrics and Gynecology 4
Pregnancy testing is necessary to rule out pregnancy as a cause of uterine enlargement or pain, as recommended by the Journal of the American College of Radiology 3
Urinalysis is suggested to exclude urinary tract infection or kidney stones that could cause left-sided back pain, according to the Journal of the American College of Radiology 3

Endometrial biopsy should be considered if the patient has abnormal uterine bleeding, particularly in perimenopausal women, to rule out endometrial pathology, as recommended by the American Journal of Obstetrics and Gynecology and the Journal of the American College of Radiology 3, 4
Assessment for rapid growth of fibroids, particularly in perimenopausal women, is necessary, as this may indicate the presence of sarcoma, with an estimated risk of 2.94 per 1,000, according to the Journal of the American College of Radiology 5

Fibroid-related causes include large posterior wall fibroids causing direct pressure on nerves or surrounding structures, as suggested by the American Journal of Obstetrics and Gynecology 4
Non-fibroid causes that should be ruled out include urinary tract pathology, musculoskeletal conditions, gastrointestinal disorders, and endometriosis or adenomyosis, according to the Journal of the American College of Radiology and the American College of Radiology 1, 3

Inadequate assessment of submucosal fibroids that may affect fertility or cause abnormal uterine bleeding should be avoided, as recommended by the American College of Radiology 6
Incomplete evaluation of the entire uterus, particularly in cases of multiple fibroids, should be avoided, according to the American College of Radiology 6
Relying solely on transvaginal ultrasound for large fibroids or an enlarged uterus without complementary transabdominal ultrasound should be avoided, as suggested by the American College of Radiology 6
Failing to consider non-gynecological causes of left-sided back pain should be avoided, according to the Journal of the American College of Radiology 3