Recent advances in the pathology of smooth muscle tumours of the uterus

Smooth muscle tumours of the uterus are common and the majority are benign leiomyomas. However, there are some tumours which exhibit unusual morpholog ical features or growth patterns that cause difficulty in their distinction from malignant neoplasms and those with endometrial stromal differentiatio n. Such lesions are reviewed in this article with detailed descriptions of their morphology, differential diagnosis and correlation with biological be haviour.