Spontaneous Resolution of an Acquired Uterine Arteriovenous Malformation in an Elderly Primigravida

Objective: Rare disease Background: Uterine arteriovenous malformation (AVM) is an uncommon lesion characterized by an abnormal connection between arterial and venous circulation that can be congenital or acquired. Acquired uterine AVMs are generally traumatic and follow delivery, abortion, curettage, or uterine surgery. Case Report: A 45-year-old female who was gravida 1 para 0 presented to our hospital with severe vaginal bleeding. Two weeks before, the patient underwent therapeutic abortion. At admission, a transvaginal ultrasound showed an unclear intrauterine lesion that spread out to the myometrium. Color Doppler evaluation demonstrated an elevated color score. Beta human chorionic gonadotropin (beta-hCG) levels were measured at admission and daily repeated, with a progressive decrease of values up to a negative level. A pelvic magnetic resonance imaging described an area of tubular and tortuous structures involving the myometrium. A computed tomography angiography confirmed the presence of a lesion infiltrating the endometrium and myometrium containing arteriovenous structures with a highly enhanced effect. Despite these findings, the patient was clinically stable. A diagnosis of uterine AVM was made and, after accurate counselling with the patient, she was discharged and underwent "watch and wait" management. After 35 days, the patient had a follow-up ultrasound that showed a complete resolution of the uterine lesion. Conclusions: AVM should be considered in the presence of heavy and sudden vaginal bleeding in a patient with risk factors for acquired AVM. A color Doppler ultrasound scan should be performed as the first approach and an expectant management should be taken into account especially with a patient of childbearing age and hemodynamic instability.