Benign metastasizing leiomyoma in triple location: lungs, parametria and appendix

Abstract

Benign metastasizing leiomyoma (BML) usually are situated in one organ, most often in lungs. BML patients typically have a history of uterine leiomyoma treated with hysterectomy, myomectomy or subtotal hysterectomy. The aim of the study was to present the case of a 53-year-old woman with triple location in the lungs, parametria and appendix. She had undergone a myomectomy 26 years earlier. In 2015, she was admitted to the surgical department because of abdominal pain, whereupon a cholecystectomy was performed. CT scans showed pelvic mass with pulmonary metastasis. Upon discharge the patient was referred to the Gynecology Clinic, where a laparotomy was performed. The intraoperative findings were: 1) uterus with multiple leiomyomas, 2) four tumors in the parametria, 3) tumor connected to the appendix. A subtotal hysterectomy, with a bilateral salpingo-oophorectomy, removal of the tumors from the parametria and appendectomy was performed. Pathology confirmed the diagnosis based on morphology and immunohistochemical staining (strongly positive for estrogen receptors and SMA, while Ki67 was very low, below 1%). Upon postoperative recovery, the patient was referred to the Thoracic Surgery Department. During the thoracotomy, multiple nodes, surrounded by lung parenchyma, were revealed. Wedge resection was performed, for localized pulmonary lesions, and sent for pathological examination. The final pathological diagnosis was benign metastasizing leiomyomatosis. In conclusion, the triple location of BML could possibly be a result of a parallel different metastasizing mechanism, although it is impossible to exclude one mechanism, which may be the cause of the metastases in three locations.

Keywords: benign metastasizing leiomyoma; etiology; triple location.

Fig. 1

CT scans: A) chest frontal scan, B) pelvic transverse scan. Arrows show lung metastases, BML show parametrial metastases

Fig. 2

Microscopic pictures of benign leiomyomas from the uterus, parametrial and appendiceal locations. A) Objective 20×, H&E, benign leiomyoma from the uterus, sparse mitotic figure in the center (mitotic activity up to 4/10 HPF); B) Objective 20×, H&E, benign adenomyoma (leiomyoma plus endometriosis) from the abdominal cavity, parametrial location; C) Objective 20×, IHCh positive staining for estrogen receptor, parametrial leiomyoma; D) Objective 20×, IHCh positive staining for SMA in parametrial adenomyoma

Fig. 3

Microscopic pictures of benign metastasizing leiomyomas (BML) from the lungs. A) Objective 20×, H&E, Well-circumscribed smooth muscle tumor is present in the lung, with the features in keeping with a benign leiomyoma, on the left showing an incorporated space with entrapped alveolar and bronchiolar epithelial lining components. B) Objective 20×, Desmin positive smooth muscle cells. The left bottom corner of the picture shows an incorporated space lined with entrapped alveolar and bronchiolar epithelial components. C) Objective 20×, Estrogen positive receptors in a benign metastasizing smooth muscle nodule. D) Objective 20×, Ki 67 index very low, below 1%