Retroperitoneal leiomyomata as a cause of bilateral hydronephrosis and lumbosciatic pain

Leiomyomas can occasionally be found in the pelvic and/or abdominal parietal retroperitoneum. This rare entity is known as retroperitoneal leiomyomata. We report the case of a 46-year-old female with bilateral hydronephrosis and chronic sciatic pain caused by invasive retroperitoneal leiomyoma 3 years after hysterectomy, and a successful outcome after treatment with surgery followed by aromatase inhibitors to control pelvic residual disease. Aromatase inhibitors could be a satisfactory treatment option after surgery to control retroperitoneal leiomyoma residual disease.

Leiomyomas are common benign tumours that arise from smooth-muscle cells around the fourth and fifth decades of life. Retroperitoneal leiomyomata is an uncommon clinical entity. In a recent review, Poliquin et al1 studied the main clinical features of 100 cases described since 1941. We describe the case of a 46-year-old woman with retroperitoneal leiomyomata recurrence 3 years after hysterectomy.2 Case presentation A 46-year-old nulliparous female was referred to our practice for follow-up after undergoing a surgical procedure for retroperitoneal leiomyomata. At the age of 42 she had undergone a hysterectomy (by laparotomy) for metrorrhagia secondary to uterine fibroids. The pathology report described two uterine leiomyoma of 4 and 5 cm each and chronic endometritis. Three years later she developed chronic right sciatic pain which required an epidural catheter placement and morphine pump to reach analgesia. Pelvic magnetic resonance imaging revealed a left pelvic mass. A second laparotomy and a unilateral left salpingo-oophorectomy were performed. The pathologist described an ovarian follicular cyst and a non-malignant leiomyoma with an atypical growth pattern in the uterine subserosa. The symptoms did not improve after surgery. One year later the patient complained of progressive leg swelling. She came to our hospital and contrast-enhanced abdominal and pelvic computer tomography (CT) (figure 1) was carried out. It showed two large heterogeneous masses in the pelvis that enclosed both ureters and caused bilateral hydroureteronephrosis. Ureteral catheters were placed to resolve the hydronephrosis. A third abdominal laparotomy was carried out. The left pelvic retroperitoneal mass measured 4×3×2 cm and was completely removed. It encircled the left ureter and affected the left vesical wall and the sigma. The sigma serosa was also resected. The right retroperitoneal pelvic mass measured 3.5×2×1 cm. It could not be totally removed. It encircled the right ureter and affected the pelvic wall, iliac vessels and the right iliac muscle. It could not be totally removed. A right salpingo-oophorectomy and a termino-terminal sigmoidectomy were performed. Replacement of the ureters in the bladder’s anterior wall was carried out. The pathology examination (figure 2) showed that both retroperitoneal tumours were formed by bundles of smooth-muscle cells with an expansive growth pattern, enclosing vessels, nerves, both ureters and the right ovary. The mitotic index (0–1/10 HPF) and the proliferative index Ki67 were both very low. There were no cytological atypia. The immunohistochemical stainings were positive for desmine, and α-1 smooth-muscle actine and vimentine. Immunohistochemical assays for oestrogens and progesterone receptors were positive in a diffuse nuclear way, and negative for protein S100, HBN-45, C-Kit, CD34 and cytokeratine markers. There were some areas of endometriosis and the intestinal serosa and the resection borders were affected. Treatment After laparotomy a CT scan was carried out which showed a residual small mass with infiltration of the right iliac muscle. Treatment with aromatase inhibitors was started as the patient had already gone through menopause and on the basis that a total suppression of oestrogens could help control the residual disease. Outcome and follow-up The sciatic pain improved after surgery and the patient needed less analgesia. Aromatase inhibitor treatment, letrozol 2.5 mg day, was initiated. Currently, the patient has been taking the medication for 23 months and is still in good health. Control CT showed an isolated and stable residual hypervascular lesion touching the right iliac muscle and vessels.

This patient had a smooth-muscle cell tumour with an invasive and unusual growth pattern.3–5 Leiomyoma can arise from the uterus and also from the pelvic and/or abdominal parietal retroperitoneum.1,6 Recent reports emphasised that retroperitoneal leiomyomata is a distinctive lesion that could derive from the mesometria smooth muscles.6–8 Recurrence of this disease is unusual after hysterectomy. The factors related to recurrence are premenopausal status, ovarian preservation and subserosal localisation of the initial lesion.2,8,9 It is very uncommon that recurrences appear as ovary and retroperitoneal masses enclosing surrounding structures.8 The main therapeutic procedure is resection of the tumour. Treatment of the residual disease is not well described. As oestrogens are suggested to play a role in the pathogenesis of the disease, treatment with gonadotropin releasing hormone agonist (GnRH analogs) has been proposed as a therapeutic approach.10 We propose that treatment with aromatase inhibitors, after oophorectomy, could be useful for management of residual retroperitoneal leiomyomata disease. Learning points Retroperitoneal leiomyomata is an uncommon clinical entity that may cause bilateral hydronephrosis and chronic pain. Recurrence of this disease is infrequent, especially after hysterectomy. Resection of the tumour is the main therapeutic procedure. Treatment with aromatase inhibitors, after oophorectomy, may be a useful way to control residual retroperitoneal leiomyomata disease. Footnotes Competing interests: None. Patient consent: Patient/guardian consent was obtained for publication.

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