A 46-year-old woman with no history of coitus presented to our clinic with severe menorrhagia and dysmenorrhea, as well as urinary frequency and pelvic heaviness. Magnetic resonance imaging revealed diffuse enlargement of the uterus with multiple bright foci, which suggested diffuse adenomyosis (Figure 1). Bilateral UAE was performed using polyvinyl alcohol particles (Bearing; Merit Medical) with sizes of 150-250 mum and 250-355 mum, followed by the use of tris-acryl gelatin microspheres (Embosphere; Merit Medical) with sizes of 300-500 mum and 500-700 mum. Embolization was performed until complete cessation of blood flow was observed for an interval of 10 heartbeats. There were no immediate post-procedural complications, and the patient was discharged uneventfully on the next day after the procedure. Two weeks later, the patient returned to the clinic with a fever of 38.5-39 C and foul-smelling vaginal discharge. Her C-reactive protein level had increased to 55.8 mg/L (normal: 0-8 mg/L), and her white blood cell count had increased to 15,060/muL (normal: 4,000-10,800/muL). Conservative treatment was initiated with a 2-week course of cefixime and metronidazole. However, the patient returned with persistent fever and leukocytosis. Pelvic computed tomography revealed complete necrosis of adenomyosis and cavitation with an air-forming abscess (Figure 2) despite the preservation of normal myometrium. The patient was hospitalized for treatment with intravenous cefotiam, amikacin, and metronidazole. After 5 days of treatment, the patient's leukocytosis and inflammatory markers improved, and she was discharged. Approximately 6 weeks after discharge, the patient returned with recurrent fever, which coincided with her first menstrual period after UAE. Follow-up computed tomography revealed a persistent abscess, although its size had decreased (Figure 3). Thus, the patient was prescribed antipyretics alone. Three days after her clinic visit, she reported vaginal expulsion of pus-like material considered as necrotic adenomyosis and subsequent improvement in fever. Symptoms of menorrhagia, dysmenorrhea, urinary frequency, and pelvic heaviness substantially improved after the expulsion of necrotic adenomyosis. Magnetic resonance imaging at 6 months after UAE showed considerable reduction in uterine size (Figure 4).