A possible progression of an atypical leiomyoma to a leiomyosarcoma

Abstract

BACKGROUND: The spectrum of uterine smooth muscle cell tumours can range from leiomyoma to leiomyosarcoma. Atypical leiomyomasare a group of tumours with cellular atypia and a mitotic indexof up to 5/HPF that are classified between the innocuous leiomyoma and leiomyosarcomas. The absence of coagulative necrosis helps to differentiate it from leiomyosarcomas.Traditionally atypical leiomyomas are thought to have a low recurrence rate. CASE DETAILS: A 41-year-old woman underwent a myomectomy for ananteriorcervical fibroid.Histology revealed a smooth muscle tumour (SMT) withdiffusely scattered hyperchromatic large cells. The maximum mitotic count was 5/10 HPF.There was no coagulative necrosis or atypical mitotic figures. It was classified as an atypical leiomyomas and had close follow up. However, 30 months later she developed heavy menstrual bleeding. The ultrasound scan revealed an anterior fibroid. She underwent a total abdominal hysterectomy with ovarian conservation. The specimen showed a well-defined myometrial nodule of 7cm with haemorrhagic areas,compressing the cervix. It was a SMT with high a mitotic activity (11-12/HPF), atypical cells with bizarre nuclei and focal coagulative necrosis confirming a leiomyosarcoma (FIGO 1B). CONCLUSION: As atypical leiomyomashave a low risk profile and are mostly found in younger women,it invariably leads to treatment that offers fertility preservation. This case challenges the generalisability of this currently held viewpoint and recommends more extensive surgery or further heightened surveillance.