Torsion of a pedunculated subserous leiomyoma: a case report of a rare cause of acute abdominal pain in a pregnant woman

Abstract

BackgroundAcute onset abdominal pain through the pedunculated leiomyoma torsion is a rather uncommon presentation and a rare source of acute abdominal pain in the emergency department during pregnancy. Due to its rarity, this condition is not always considered, leading sometimes to inappropriate or unnecessary therapeutic approaches. Given that there are no specific clinical findings, radiological examination represents a fundamental tool for achieving the correct diagnosis. Pelvic ultrasound is usually the first imaging approach, but MRI is recommended for further evaluation, showing high diagnostic accuracy.Case presentationA 35-year-old primigravid woman presented at the gynecological emergency department at 21 weeks of gestation, with a complaint of sudden onset of strong intensity right abdominal pain. Vital signs and blood test results were normal. A pelvic ultrasound was requested and showed a heterogeneous pelvic mass in the right lower quadrant, between the uterine body and the right ovary (which was not enlarged and presented normal venous and arterial blood flow) raising the suspicion of a right ovary tumor or an exophytic uterine tumor. An MRI was performed and revealed a well-defined and heterogeneous mass, with predominantly high signal intensity on T2-weighted images (WI) with and without fat saturation and with hyperintense areas on axial T1WI; the presence of bridging vessels in the interface between the tumor and the uterus was also demonstrated—the “bridging vessel sign.” The tumor presented restricted diffusion with high signal intensity on axial diffusion-weighted imaging (b1000) and low signal intensity on the axial ADC map. The set of MR imaging features was consistent with the torsion of a pedunculated subserosal uterine leiomyoma with hemorrhagic necrosis. A successful conservative approach was the first-option treatment, with no further surgical intervention.ConclusionThe torsion of a pedunculated subserous leiomyoma should be considered in a pregnant woman with acute onset abdominal pain. The correct diagnosis, based on clinical and radiological findings, is essential for good outcomes concerning maternal and fetal well-being, allowing the safest and most appropriate treatment. A conservative approach seems to be a safe and appropriate first-option treatment to this condition.