Unusual Broad Ligament Leiomyoma

Author Information

Swaminathan G*, Parulekar SV**.
(* Specialty Medical Officer, ** Professor and Head, Department of Obstetrics and Gynecology, Seth G S Medical College & KEM Hospital, Mumbai, India.)

Abstract
Extrauterine leiomyomas may develop in the broad ligament or at any other site where smooth muscle is present. Primary broad ligament tumors are rare and these pose diagnostic difficulties due to their rarity. Broad ligament is the most common extrauterine site for the occurrence of a leiomyoma. We report a case of a 47 year old woman with a large right sided true broad ligament leiomyoma. On the basis of clinical examination and ultrasound, a provisional diagnosis of uterine leiomyoma was made. On laporotomy, it was found to be a large 18*15*10 cm size leiomyoma in the right broad ligament for which enucleation of leiomyoma was done followed by total abdominal hysterectomy.

Introduction

Leiomyomas are the most common uterine tumors, most commonly found during the reproductive years. They are smooth muscle tumors which are benign in nature. They can be either  intrauterine or extrauterine. The classification is mainly determined by the site of its origin and the direction of growth. They are broadly classified into three main types :  interstitial, subserous and submucous. Entities called as extra-uterine leiomyomas exist but they are not as common as uterine leiomyomas. Extra-uterine leiomyomas may develop in the broad ligament or at any other site where smooth muscle is present.[1] Primary broad ligament tumors are rare. They pose specific diagnostic difficulties due to their rarity. Tumors of broad ligament are mostly epithelial in nature and mesenchymal tumors are less common. The commonest mesenchymal tumors found in the broad ligament are leiomyomas.[2] The true incidence of broad ligament leiomyomas is not known. They can cause a variety of symptoms like menstrual irregularities and pressure effects.[1,2] Usually the diagnosis of broad ligament leiomyomas can be made clinically and confirmed by imaging. If not, it is evident during a laparotomy. We present a case in which it was missed clinically, by imaging and was very difficult during a laparotomy.

Case Report

 A 47 year old para 3 living 3 with previous 3 full term normal deliveries came to our outpatient clinic with complaints of abnormal uterine bleeding. She had complaints of menorrhagia since 3 cycles with menses every 15-20 days lasting for 5-6 days with soakage of 5-6 pads per day and passage of clots. She also had complaints of pain in abdomen in right flank and hypogastric region which was dull aching in nature since 15-20 days. She also had frequency of micturition for 1 month. On examination her general condition was fair, vital parameters were within normal limits, and there was no abnormality on systemic examination. On abdominal examination, there was a nontender lump of around 16-18 weeks of gestation arising from the pelvis. On per speculum examination, cervix and vagina were healthy and there was minimal bleeding through os. On bimanual pelvic examination, a single large intramural leiomyoma 5-6 cm in diameter was felt posterolaterally on right side. Ultrasound scan of pelvis was suggestive of an enlarged uterus with multiple intramural uterine leiomyomas. A provisional diagnosis of uterine leiomyomas with abnormal uterine bleeding was made and decision was taken for total abdominal hysterectomy with bilateral salpingectomy. Investigations for fitness for anesthesia were normal. A laparotomy was done. Intraoperatively, there was a large 10x12 cm sized mass on the right side and midline. The uterus and adnexal structures were not found. We were called for assistance at that stage. We found that the mass was covered by peritoneum and had large vessels on the surface. It was not mobile, which suggested that it was extraperitoneal. Its relationship to the uterus was not apparent because the uterus was not seen. Further examination after enlargement of the abdominal incision showed that the uterus was of normal size and shape and was situated within the pelvis, below and to the left of the mass. There was no apparent connection between the uterus and the mass. The fallopian tubes and ovaries were normal. A diagnosis of a right sided true broad ligament leiomyoma was made. 


Figure 1. Showing uterus (U) and right broad ligament leiomyoma (M), ovaries (O) and fallopian tubes (F), which have been dragged up by traction with a clamp applied to the left cornual structures.

The right broad ligament was opened by clamping, cutting and ligating the right round ligament. The leiomyoma was dissected and removed after locating the right ureter, which was found to be below and lateral to the leiomyoma. Then total abdominal hysterectomy and bilateral salpingectomy was done. Hemostasis was achieved in the bed of the leiomyoma. A drain was kept in the right broad ligament and the abdomen was closed. The patient made an uneventful recovery. The leiomyoma weighed 1150 g. Histopathological examination confirmed the diagnosis of a uterine leiomyoma. The uterus and fallopian tubes showed normal histology.


Figure 2. Enucleation of broad ligament leiomyomyoma.


Figure 3. Broad ligament leiomyoma specimen.

Discussion

Broad ligament is a peritoneal fold  consisting of two layers that connects the sides of uterus to the lateral walls of the pelvis and its floor.[3] Epithelial tumors are the commonest broad ligament tumors, whereas mesenchymal tumors are extremely rare. Among the mesenchymal tumors, the commonest one is leiomyoma.[4] Broad ligament leiomyomas are of two types. A primary/true broad ligament leiomyoma arises from the smooth muscle fibers that are normally found in the tissues in the broad ligament. It can attain a very big size and may distort the fallopian tube and compress the ureter causing hydroureter and hydronephrosis. But it is entirely separate from the uterus. Hence it can displace the uterus, but not distort it. The anatomical relationship of the uterine vessels and ureter to such a leiomyoma is variable. Hence there is serious risk of injury to the ureter if it is not located and protected prior to clamping, cutting or ligating anything in the broad ligament. A secondary/false broad ligament leiomyoma arises mostly from the lateral walls of the uterus or the cervix and grow laterally between the two layers of the broad ligament but retains its attachment to the uterus. The uterine vessels and ureter lie lateral to the tumor.[5] Such a tumor has a pseudocapsule. Hence when it is enucleated within the pseudocapsule, there is no risk of injury to the ureter.
Making a diagnosis of broad ligament leiomyomas is always a challenge.[6] The most useful modalities for diagnosis are ultrasound (USG), computed tomography (CT) and magnetic resonance imaging (MRI). On imaging, “bridging vessel sign” is helpful in the diagnosis of a leiomyoma.[2] Transvaginal ultrasound can diagnose broad ligament leiomyoma because it allows clear visual separation of the uterus and ovaries from the mass. On ultrasound, a broad ligament leiomyoma usually presents as a well circumscribed hypoechoic solid mass with a whorled appearance, with variable echogenicity depending on the extent of calcification and degeneration. Pedunculated leiomyomas may be mistaken for solid ovarian masses on ultrasound, MRI is indicated in such circumstances.[7] On MRI, broad ligament leiomyomas have the typical appearance of leiomyomas and are seen as sharply emarginated lesions of low signal intensity on both T1W and T2W sequences due to their high fibrotic content. They are usually not surrounded by a pseudocapsule and do not show interface vessels which are imaged as perilesional rim enhancement. The differential diagnosis is with parasitic leiomyoma of the broad ligament, subserosal leiomyomas, masses of ovarian origin, fibrotic adnexal lesions and other solid tumors from the broad ligament. Parasitic leiomyomas of the broad ligament usually originate from the uterus and they invade the broad ligament, additionally recruiting own arterial supply, and either maintaining or losing their original uterine attachment. Pedunculated subserosal leiomyomas, may be hard to distinguish from broad ligament leiomyomas; thus identification of the site of attachment is crucial to establish the uterine origin. Differentiation of a true broad ligament leiomyoma from other pelvic extraperitoneal tumors is essential for the patients’ further management.

It was a large true broad ligament leiomyoma in our case. Broad ligament leiomyomas have the potential to grow to a large size[8]. We did not do CT or MRI because the diagnosis was apparently clear clinically and was confirmed by USG. Routine use of CT and MRI is not possible in resource poor healthcare facilities. The nature of the tumor could not be determined by the operating surgeon because the uterus and adnexal structures were not seen anywhere. Finally it was found that the leiomyoma was growing from above the level of the uterine vessels and had continued to grow cranially after displacing the normal-sized uterus and its adnexal structures downward and to the left. These structures were hidden below the large mass. Since they serve as a landmark for a gynecologist while dealing with intraperitoneal as well as extraperitoneal pelvi-abdominal masses, their localization is an important step in the management of such masses. Surgery is challenging in case of broad ligament leiomyomas because of their location and size, especially since surrounding organs like ureters, urinary bladder and intestines may be at risk. It is very important to identify the ureteric course during surgery. Also, leiomyoma may be adherent to surrounding structures and therefore lead to greater risk of inadvertent injury.[1]

Conclusion

True broad ligament leiomyoma is a tumor that can be challenging  in both its diagnosis and management. Identification of the uterus and adnexal structures is crucial in determining the source of the tumor during a laparotomy. Though imaging modalities are helpful, the final diagnosis needs to made intraoperatively and confirmed by histopathological examination.

References
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  4. Thor AD, Young RH, Clement PB. Pathology of fallopian tube, broad ligament, peritoneum and pelvic soft tissues. Hum Pathol 1991;22: 856–67.
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  7. Fasih N, Prasad Shanbhogue AK, Macdonald DB, Fraser-Hill MA, Papadatos D and Kielar AZ. Leiomyomas beyond the Uterus: Unusual Locations, Rare Manifestations. Radiographics, 2008;28, 1931-1948.
Citation

Swaminathan G, Parulekar SV. Unusual Broad Ligament Leiomyoma. JPGO 2017. Volume 4 No. 11. Available from: http://www.jpgo.org/2017/11/unusual-broad-ligament-leiomyoma.html