Lipoleiomyoma: a rare benign tumour of the uterus.

To cite: Johari B, Koshy M, Sidek S, et al. BMJ Case Rep Published online: [please include Day Month Year] doi:10.1136/bcr-2014205814 DESCRIPTION A postmenopausal 68-year-old woman was presented with intermittent left-sided abdominal discomfort. She denied any vaginal bleeding, dysuria, changes in bowel habits or constitutional symptoms. There was no family history of malignancy. The clinical examination revealed a cheerful, noncachexic patient with normal vital signs. Her abdomen was soft with no masses palpable. An abdominal and pelvic ultrasound was performed, revealing a markedly hyperechoic mass encased by hypoechoic rind situated posterior to the urinary bladder (figure 1). No significant vascularity was seen within this mass on Doppler study. The contrasted CTof the abdomen confirmed the presence of a large well-defined soft tissue lesion of benign appearance arising from the posterior wall of the uterus. Based on the appearance and density in Hounsfield units, it was composed of a predominantly fatty component (figure 2). The size of the lesion was 6.3×8.3×7.3 cm (width×thickness×length). The endometrium and ovaries were normal. There was no pelvic lymphadenopathy or ascites. As the CT confirmed the uterine origin and characteristic predominant fatty component of the tumour, the patient was diagnosed with benign uterine lipoleiomyoma. Tumour markers such as CA-125 (cancer antigen 125), α-fetoprotein, CEA (carcinoembryonic antigen), β-hCG (human chorionic gonadotropin) and lactic dehydrogenase (LDH) were normal. The patient opted for conservative treatment and did not want surgery. Uterine lipoleiomyoma, a benign fatty tumour of the uterus, is rare, with the overall incidence reported between 0.03% and 0.2%, and comprising of 0.35% of uterine myomatous tumours. It is mostly described as a variant of uterine leiomyoma with similar clinical course and presentation, and is typically found in postmenopausal patients. Histologically, these tumours are composed of variable amounts of smooth muscle, fat cells and fibrous tissue, developing likely secondary to fatty metamorphosis of smooth muscle cells of leiomyomas. Lipoleiomyomas have also been reported to occur in the uterine cervix, broad ligament, retroperitoneum and ovary. Apart from uterine lipoleiomyomas, the main differential diagnoses of fat containing pelvic mass in a female are benign cystic ovarian teratomas, followed by other lipomatous ovarian tumours, pelvic lipomas and liposarcomas. 4 5 There have been reports to suggest an association between lipomatous uterine tumours and endometrial carcinomas; however, it is