MIXED LOW-GRADE AND HIGH-GRADE ENDOMETRIAL STROMAL SARCOMA OF UTERUS - DIFFERENCES ON IMMUNOHISTOCHEMISTRY AND CHROMOSOME IN-SITU HYBRIDIZATION

A case of a 64 year old woman with a tumour of the uterus is reported. The patient presented with postmenopausal bleeding and subsequently u nderwent total hysterectomy and bilateral salpingo-oophorectomy. Secti ons of the tumour showed a low grade endometrial stromal sarcoma coexi sting with areas consistent with high grade sarcoma. The sarcoma cells , in both the low and high grade areas, were positive for vimentin and negative for desmin and cytokeratin on immunohistochemistry. While th e sarcoma cells in the low grade region showed immunoreactivity for oe strogen and progestogen receptors, those in the high grade region did not, Using chromosome in situ hybridisation, the low grade portion of the sarcoma was diploid for chromosomes X, 11, 12, and 17, whereas the more anaplastic areas were aneuploid for these chromosomes, This case may represent an example of high grade endometrial stromal sarcoma ar ising by dedifferentiation from a low grade stromal sarcoma, Adequate sampling is important in identifying such anaplastic changes as the or igin of the tumour will affect patient management.