Uterine leiomyoma is the most common benign gynecological tumor affecting as many as 25% of women in the reproductive age group [
6], and is present in about 80% of all hysterectomy specimens [
7]. In addition to the traditional patterns of leiomyomatous growth in the uterus, some unusual extra-uterine growth presentations are mentioned in the literature; benign metastasizing leiomyoma, disseminated peritoneal leiomyomatosis, intravenous leiomyomatosis, parasitic leiomyomata and retroperitoneal growth [
8]. The incidence of retroperitoneal leiomyomata is quite low, and it is even lower for those extending to or originating in the abdomen. Of the reported retroperitoneal leiomyomata, 73% are located in the pelvis [
9]. Most of the published case reports diagnosed the cases clinically as retroperitoneal growths with high suspicion of malignancy without suspecting their leiomyomatous nature [
10‐
15]. The origin of such tumors is a puzzling issue with much scientific debate. Poliquin and coworkers observed a 40% association of retroperitoneal leiomyomas with uterine counterparts or a history of hysterectomy due to uterine leiomyomata [
9]. Zaitoon suggested the parasitic theory for such tumor growth [
10] while Stutterecker
et al. claimed that Müllerian cell rests or smooth muscle cells in the retroperitoneal vessels wall are the putative origin [
12]. Kho and Nezhat proposed an 'iatrogenic' origin for such growths while analyzing a case series of extra-uterine leiomyomata, mostly of retroperitoneal or intraperitoneal location with no visible connection to the uterus. They found out that 83% of their case series had previous abdominal operations, and 67% had myomectomies, most of them via laparoscopy with morcellation [
16]. In our reported case, although the iatrogenic theory for such leiomyomata could explain the growth of the numerous pedunculated subserosal leiomyomata scattered on the uterine surface (Figure
2), it cannot explain the growth of the retroperitoneal mass which was completely separable from the uterus and seated deep in the posterior abdominal wall peritoneum. The concept suggested by Stutterecker
et al. is the more accepted explanation for such a location for the growth of a leiomyoma [
12].