Intravascular leiomyomatosis is a rare disease with low morbidity and can be easily misdiagnosed. This study focused on exploring the ultrasonic features of intravascular leiomyomatosis beyond uterus, with the purpose of improving the recognition and diagnosis of intravascular leiomyomatosis.

Forty-three cases of intravascular leiomyomatosis confirmed by postsurgical pathological examinations in Peking Union Medical College Hospital from July 1, 2014 to July 1, 2018 were selected, which all had venous involvement detected by ultrasound. Both clinical data and ultrasonic features of 43 cases of intravascular leiomyomatosis were retrospectively analyzed. The main observational items include clinical symptoms, size of lesion, length, extent and range of involvement, echo types and blood flow signals inside the lesion. Forty-three patients were all female, of which 27 patients had a history of hysteromyoma (7 myomectomy and 20 hysterectomy) and 16 without any related gynecologic surgeries.

The clinical symptoms of these cases varied, which manifested as dyspnea and palpitation (n=11), abdominal pain and distension (n=11), edema of lower extremity (n=6), pelvic lumps (n=5), paroxysmal syncope (n=2), irregular vaginal bleeding (n=2), frequent urination (n=1) and no clinical symptoms (n=5). Ultrasonography showed 43 patients all had visible masses at the site of the inferior vena cava or iliac vein detected in the lumen, of which 42 cases were correctly diagnosed with intravascular leiomyomatosis by ultrasound before operation The length of lesion varied, and the longest one rooted from pelvic to right atrium via venous system in some patients. Color Doppler flowing imaging demonstrated a bundle of fine blood flow between the lesion and venous wall. Of all the patients, 31 had right atrial involvement, and 1 had both right atrial and right ventricle involvement. Thirty-six had lumps of hypoechogenicity or mixed echogenicity rooted in pelvic or uterus.

Intravascular leiomyomatosis is a kind of rare disease with no specific clinical symptoms, while it can be presented with specific ultrasonic features when expanding beyond uterus. Therefore, the identification of the ultrasonic features outside the uterus can play a significant role in the preoperative diagnosis of intravascular leiomyomatosis in ultrasound diagnosis.