A case of well differentiated endometriod adenocarcinoma of the endometrium with a synchronous endometriod and clear cell adenocarcinoma of both ovaries was reported. Recently, a 28-year-old woman presented with vaginal bleeding was diagnosed to have only FIGO stage IaG1 (FIGO 2000) cancer of the endometrium.
After 3 months of high dose progestin treatment, 15 cm bilateral ovarian tumors later diagnosed as FIGO stage IIIa ovarian cancer (mixed endometriod and clear cell adenocarcinoma) were detected, and later surgically removed. The patient then was started on Placitaxel/Carboplatin combination chemotherapy for 6 cycles after surgery.
The synchronous cancers of endometrium and ovary are usually presented in woman with median age of 50 with obesity, diabetes, and hypertension. These low grade tumors and better prognosis are the norm in contrast to the authors’ case with clear cell component and higher stage of ovarian cancer in young lean Thai woman.

Keywords: Endometrial cancer, Ovarian cancer, Synchronous tumor of endometrium and ovary