Clinical history: This is a 56 year-old woman with a biopsy-proven FIGO grade 1 endometrial adenocarcinoma. She had an uncomplicated TAH/BSO with staging.
What is the most probable diagnosis?
Benign intramural lipoleiomyomata
There are numerous subtypes of leiomyomata. Lipoleiomyomata are a rare, mixed heterologous benign tumours that typically occur in perimenopausal and menopausal women. They are usually asymptomatic, but can present with pelvic pain, abnormal uterine bleeding or as a palpable mass.
Grossly the lesions resemble typical leiomyomata, but are yellowish in appearance. Microscopically, there is smooth muscle admixed with varying amounts of mature adipose tissue within a well-circumscribed nodule. There may be a single lesion, or more commonly, multiple small lipoleiomyomata. Often they are an incidental finding.
Differential diagnoses include lipomatous degeneration or smooth muscle metaplasia. Extremely rare cases of liposarcoma arising in a lipoleiomyoma have been described. Adipose tissue in the myometrium on routine biopsy should also raise concerns over potential perforation during the procedure.