Mistoid Cystic Degeneration of a Leiomyoma: About a Case with Intramyometric Evolution in the Gynecology Department of the Owendo University Hospital (Gabon)

Objective : We report a case of mixoid cystic degeneration of a FIGO 4-rated uterine fibroid simulating a polymyomatous uterus.

Observation : 48-year-old patient, paucipare and a myomectomy 3 years ago, received on March 11, 2025 for abdominal distension evolving for 4 years associated with lumbopelvic pain. This symptomatology had motivated several consultations and the diagnosis of ovarian tumor evoked. On general examination, we find a mucocutaneous pallor, the blood pressure was 125/75 mmHg, and the weight was 67kg. The abdomen was very distended by a firm, regular, and mobile mass. The haemoglobin level was 9.9 g/dl, the hepatorenal balance was normal and the CA 125 was positive.

Abdominal ultrasound revealed a mixed echogenicity tumor with a thick shell without vegetations. Computed tomography (CT) had noted the presence of a large, hypodense, fluid mass with no visible septa. A laparotomy reveals a large uterus with regular parities without visible cystic structure, the ovaries are atrophied. A sagittal section had shown a uterine wall blown by a smooth-walled cystic structure and containing a citrine fluid. The diagnosis of mixoid proliferation of myomatous cells without cellular atypia had been retained by pathological anatomy.

Conclusion : Mixoid cystic degeneration of uterine fibroids is rare. Forms with intramyometrial evolution are exceptional. This must be considered in view of the globular and regular nature of the uterus with no apparent lesions.

Keywords: Myomas, Cyst, Mixoid, MRI, Benign.