Volume 154, Issue 1 , Pages 114-115, January 2011
Benign metastasizing leiomyoma of external iliac vessels: an unusual case report
Article Outline
Dear Editor,
Uterine smooth-muscle tumours with unusual growth patterns are rare and include a variety of neoplastic lesions histologically characterized by their similarity to adult smooth-muscle tissue. They include three primary neoplasms: intravenous leiomyomatosis, benign metastasizing leiomyoma (BML), and leiomyomatosis peritonealis disseminata. BML of the uterus is a rare but well recognized entity, which has been described primarily in women of reproductive age [1]. We illustrate a case of retroperitoneal leiomyoma encasing the right iliac vessels.
A 42-year-old woman was referred with a 10-month history of metrorrhagia refractory to medical therapy, lower abdominal cramping and some lower extremity edema. The patient's medical history was relevant for severe obesity (BMI
=56.6), hypertension, diabetes, and breast cancer for which she had undergone a quadrantectomy followed by chemotherapy and radiotherapy. Other points in the history were: menarche at 11, gravida 4, para 3 (three caesarean sections), uterine myomectomy during the second caesarean section, and one miscarriage. Recently she had undergone four uterine curettages.
Physical examination showed an abdominal mass due to an increase in uterine size (as for a 24-week pregnancy). High-definition digital computed tomography of abdomen and pelvis was performed instead of MRI because of the patient's obesity. It revealed a large, expansive, solid, mass with irregular contour in the pelvis, 10.5cm×7.0cm×6.5cm in size. The mass was not clearly dissociable from the uterus and had a whorled appearance suggestive of a broad ligament myoma. A chest X-ray was negative for any diseases. Tumour markers were normal. The patient had been treated with GnRH agonists because of anemia, but metrorrhagia was refractory to medical therapy.
The indication for laparotomy was the uterine size and the presence of a large retroperitoneal mass. Embolisation of the uterine artery could be a good procedure for treatment of metrorrhagia and myoma when it is surgically dangerous to operate; in this case we felt removal of the uterus to be necessary because of the patient's complaints and removal of the mass in order to obtain histology and rule out malignancy.
At laparotomy, the ovaries and tubes were found to be intrinsically normal on both sides; the uterus was increased in size, and displaced toward the left hemipelvis by a huge right infraligamentary mass which was separate from the uterus. The uterus was removed. After opening the anterior leaf of the right broad ligament a smooth, tight tumour encasing the right iliac vessels was identified as a serendipitous finding during surgery, so we had not planned the presence of a vascular surgeon. We do pelvic vascular surgery on our own as part of oncology surgery. In this specific case, as we usually do, we consulted our consultant vascular surgeon, who scrubbed with us. The right iliac vessels were clamped, divided and cut. Upward traction was applied to the tumour and gradually, by cutting many fine adhesions involving the peritoneum and ascending mesocolon, the mass was entirely shelled out. At this point the right iliac artery was reconstructed using a knitted polyester vascular prosthesis, and the right external venous area was closed. The abdomen was closed. The patient was discharged four days after the operation in excellent condition.
On gross examination, the tumour consisted of a large, nodular, whitish mass, measuring 10.5cm×7.0cm×6.0cm. On cutting, the tissue appeared to be fairly uniform in consistency, its fine, whorled architecture suggesting that of a myoma. The entire mass weighed 420g. (Fig. 1) Microscopic observations of the tumour confirmed histopathological similarity to the benign uterine myomas removed during the previous myomectomy, it showed a proliferation of bands of spindle cells crossing each other at right angles, extensive areas of hyalinization interspersed between bundles of benign-looking smooth muscle cells showing moderate cellularity, minimal atypia, inconspicuous mitosis, and no evidence of necrosis. The tumour encased vessels of middle gauge.
Fig. 1.
Retroperitoneal leiomyoma encasing the right iliac vessels.
Most BMLs are asymptomatic and are discovered incidentally or when an acute complication, usually pulmonary, develops. BML is commonly diagnosed 3 months to 20 years after hysterectomy because of fibroids. The clinical course is indolent and death is associated with unrelated but concomitant disease. There are reports of benign metastasizing leiomyomas in the lungs, skull base and spine, the lymph nodes of the small pelvis and the heart [2], [3], [4], [5]. Retroperitoneal leiomyoma differs from the intraligamentary leiomyoma of uterine origin because it lies free between the peritoneal leaves and has no attachment to the uterus. Our case contributes to the literature because the retroperitoneal leiomyoma described was in an unusual anatomic position, adherent to the pelvic right wall and encasing the right iliac vessels with important surgical implications, due to the necessity for blood vessel reconstruction.
References
- Uterine leiomyomas: racial differences in severity, symptoms and age at diagnosis. J Reprod Med. 1996;41:483–490
- . Benign metastasizing leiomyoma of the uterus: histologic and immunohistochemical characterization of primary and metastatic lesions. Arch Pathol Lab Med. 1999;123:960–962
- . Benign metastasizing leiomyomatosis diagnosed by echocardiography. Echocardiography. 2002;19:571–572
- . Benign metastatic leiomyoma. Clin Radiol Extra. 2004;54:29–31
- . Benign metastasizing leiomyoma causing spinal cord compression. Surg Neurol. 2003;60:575–577
PII: S0301-2115(10)00375-1
doi:10.1016/j.ejogrb.2010.07.041
© 2010 Elsevier Ireland Ltd. All rights reserved.
Volume 154, Issue 1 , Pages 114-115, January 2011
