A case of spontaneous parasitic myoma in a patient without a history of myomectomy treated laparoscopically

Abstract

Parasitic myoma (PM) is a rare disease in which multiple leiomyomas are intraperitoneally formed. Recently, an increasing number of cases due to specimen morcellation during minimally invasive surgery has been reported. We present the first case of a PM identified intraoperatively during laparoscopic hysterectomy. A 40-year-old Japanese multiparous woman presented to our hospital with heavy menstrual bleeding. She had no history of previous surgery. Magnetic resonance imaging showed uterine myomas. As the patient did not wish for further pregnancy, she underwent oral gonadotropin-releasing hormone antagonist therapy followed by a total laparoscopic hysterectomy. Intraoperatively, we identified a thumb-sized tumor on the left side of the peritoneum. Histopathological examination showed evidence of benign leiomyoma.

Keywords: gonadotropin-releasing hormone; hysterectomy; laparoscopic surgery; myoma; parasitic myoma.

Fig. 1.

Sagittal T2-weighted MRI Magnetic resonance imaging (MRI) showing enlarged uterine myomas that occupy the pelvic cavity (arrow).

Fig. 2.

Intraoperative laparoscopic image After laparoscopic hysterectomy is completed, we identified a thumb-sized tumor on the left side of the peritoneum (arrow). The patient had no previous surgical history.

Fig. 3.

Pathological findings for the resected tumor of the left side peritoneum. Hematoxylin and eosin, ×200 objective. Typical microscopic view of a benign leiomyoma, with no necrosis and without marked atypia (3a). The immunohistochemical evaluation of the resected tumor is positive for smooth muscle actin (3b), estrogen receptor (3c), and progesterone receptor (3d).

Fig. 4.

Coronal T2-weighted MRI After laparoscopic surgery, we reviewed the MRI scans taken before surgery. T2 weight MRI lesion indicates the presence of a 1.8 × 1.0 cm low-density solid tumor in the left peritoneum, apart from the uterine and uterine myoma (arrow).