Fallopian tube deciduosis with massive hemoperitoneum in a second-trimester pregnancy: a case report of ultrasound findings

Abstract

Deciduosis is a decidual reaction outside the uterus that typically occurs during pregnancy. It is usually asymptomatic, but several life-threatening complications have been reported. Imaging features of this condition are lacking. This case report describes the ultrasound and clinical findings in a pathologically confirmed case of deciduosis. A 28-year-old primigravida with 23 weeks of gestation was referred to our department with severe abdominal pain. Pelvic ultrasound showed a left-sided, oval, well-circumscribed, solid, heterogeneous, predominantly hypoechoic pelvic mass without vascularity. There was abundant free fluid in the perihepatic and perisplenic spaces. The patient went into hypovolemic shock, leading to emergency surgery. Active bleeding from the left fallopian tube and a large hemoperitoneum of 1500 ml were found in this area and evacuated. A congestive fallopian tube with an arborescent zone and bleeding near the fimbria was removed. The histopathological features of the left salpingeal mass were consistent with decidual tissue surrounded by a hematoma. This case report is the first in Mexico to emphasize the imaging findings of this entity. It is presented as an educational tool that highlights deciduosis as a potential differential diagnosis in the emergency abdominopelvic ultrasound of pregnant patients.