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Genesis of True Broad Ligament Leiomyoma

Author Information

Parulekar SV
(Professor and Head. Department of Obstetrics and Gynecology, Seth G.S. Medical College and K.E.M Hospital, Mumbai, India.)

Abstract

Leiomyomas are benign tumors arising from the myometrium affecting up to 30% of all women in the reproductive age group. Broad ligament leiomyomas account for less than 1% all leiomyomas. True broad ligament leiomyomas are conventionally believed to develop from mesenchymal remnants founding the broad ligament, or smooth muscle in the media of blood vessels. A new theory of development of a true broad ligament leiomyoma is presented.

Introduction

Leiomyomas are benign tumors arising from the myometrium affecting up to 30% of all women in the reproductive age group. Broad ligament leiomyomas account for less than 1% all leiomyomas. A false broad ligament leiomyoma develops laterally from the lateral surface of the uterus. A  true broad ligament leiomyoma is conventionally believed to develop from mesenchymal remnants founding the broad ligament, or smooth muscle in the media of blood vessels in the broad ligament. A case that supports conversion of a false broad ligament leiomyoma into a true broad ligament leiomyoma is presented. It is proposed that elongation and thinning of the pedicle of a false broad ligament leiomyoma finally results into its necrosis so that the leiomyoma loses its attachment to the uterus and gets classified as a true broad ligament leiomyoma.

Theory

It is theorized that sometimes a true leiomyoma develops by severance of the pedicle of a false broad ligament leiomyoma.

Discussion

Leiomyomas are benign tumors arising from the myometrium. They affect up to 30% of all women in the reproductive age group. Extra-uterine leiomyomas are rare. Broad ligament leiomyomas are the most common tumors among the extra-uterine leiomyomas, though their overall incidence is less than 1%.[1]  These are the most common forms of mesenchymal tumors found in the broad ligaments.[2] But mesenchymal tumors are rare in the broad ligaments, the most common type being epithelial tumors.[3] Broad ligament leiomyomas are of two types- false and true. The main difference between the two is that a false one has a pedicle connecting it to the uterus, while a true type has no connection with the uterus. Distinction between the two types is not merely of academic interest. A false broad ligament leiomyoma usually lies above the uterine vessels, and when it enlarges, the ureter lies below and lateral to it. A true broad ligament leiomyoma develops anywhere in the broad ligament, and hence the ureter can lie above, below, medial, or lateral to the leiomyoma. Localization of the ureter with respect to the broad ligament leiomyoma is essential prior to dissection, cutting and ligation of any tissue around the leiomyoma, so that ureteric injury is prevented. Another reason for making the distinction preoperatively is that a false broad ligament leiomyoma has a pseudocapsule, so that when the pseudocapsule is divided and dissection is done within the pseudocapsule, the leiomyoma can be enucleated without any fear of injuring the ureter. A true broad ligament leiomyoma does not have a pseudocapsule, and its enucleation is much more difficult than that of a false broad ligament leiomyoma, and also associated with a greater risk of injury to the ureter.[4]
False broad ligament leiomyomas arise from the lateral walls of the uterus or supravaginal cervix, and grow laterally into the broad ligament.[5] True broad ligament leiomyomas are said to develop from the mesenchymal remnants founding the broad ligament, or smooth muscle in the media of blood vessels.[6]


Figure 1. False broad ligament leiomyoma on the left side of the uterus, exposed by opening the left broad ligament. The long, narrow pedicle is seen connection the leiomyoma to the lower, lateral surface of the uterus.


Figure 2. Hysterectomy specimen of the same case. The pedicle is 5 cm long and a few millimeters in diameter.

In the case presented here, the false broad ligament leiomyoma had a 5 cm long pedicle which measured a few millimeters in diameter. Considering the size of the leiomyoma, it appeared that the blood supply to the leiomyoma through the vessels in that thin pedicle would reduce to almost nil after the pedicle elongated and thinned further. Finally when the leiomyoma acquired its blood supply through the blood vessels in the connective tissue of the broad ligament, the long pedicle would necrose and the leiomyoma would have no connection with the uterus. This an original false broad ligament leiomyoma would get converted into a true broad ligament leiomyoma.
This is the first demonstration of elongation and thinning of the pedicle of a false broad ligament leiomyoma almost to the point of its necrosis, so that the leiomyoma would lose its connection with the uterus. Thus it is likely that all true broad ligament leiomyomas do not necessarily develop from mesenchymal remnants or smooth muscle in the media of blood vessels in the broad ligament, and some of them develop due to necrosis of their pedicles connecting them to the lateral surface of the uterus.

Acknowledgements

I thank Dr Shruti Kulkarni for taking the photographs used as illustrations in this article.

References

1.      Kumar P, Malhotra N. Tumors of the Corpus Uteri. In Jeffcoate's Principles of Gynecology. 7th Ed. New Delhi: Jaypee Brothers Medical Publishers (P) Ltd. 2007. pp 487-516.
2.      Breen JL, Neubecker RD. Tumors of round ligament: A review of literature and a report of 25 cases. Obstet Gynecol 1962;19:771-80.
3.      Thor AD, Young RH, Clement PB. Pathology of fallopian tube, broad ligament, peritoneum and pelvic soft tissues. Hum Pathol 1991;22:856-67.
4.      Parulekar SV. Practical Gynecology and Obstetrics. 5th ed. Mumbai: Vora Medical Publications; 2011. p 348
5.      Parker  WH.  Uterine  myomas:  an  overview  of  development, clinical features, and management. Obstet Gynecol 2005;105:216-7.
6.      Heinzman AB. Pelvic Mass. In Hoffman BL, Schorge JO, Schaffer JI, Halvorson LM, Bradshaw KD, Cunningham FG, editors. Williams Gynecology. 2nd ed. New York: McGraw-Hill. 2012, pp 247-259.

Citation

Parulekar SV. Genesis of True Broad Ligament Leiomyoma. JPGO 2014 Volume 1 Number 8. Available from:  http://www.jpgo.org/2014/08/genesis-of-true-broad-ligament-leiomyoma.html