Laterally extended endopelvic resection as part of the surgical management of disseminated retroperitoneal leiomyomatosis mimicking low-grade sarcoma in a patient with a solitary kidney.

Leiomyomas are common benign uterine smooth muscle tumours. Rarer subsets may demonstrate aggressive extrauterine growth which mimic metastatic disease. We discuss the case of a female patient in her 40s, with a long-standing atrophic right kidney, presenting with a 17 cm uterine mass demonstrating bilateral para-aortic and pelvic sidewall spread. Although biopsies favoured the diagnosis of a benign tumour, a leiomyosarcoma could not be excluded. The surgical complexity of the case was compounded by a tumour residing close to the only functioning kidney and engulfment of the inferior mesenteric artery. The surgical procedures indicated were a radical hysterectomy, the laterally extended endopelvic resection procedure to achieve clear margins in the pelvic sidewall and a left hemicolectomy. In the absence of formal guidelines, we present this challenging case to provide clarity into the histological assessment and surgical management of rare leiomyomas, as well as an overview of the current literature.