後腹膜原発と考えられた類内膜癌の1例

A case of primary retroperitoneal endometrioid carcinoma

後腹膜のミュラー管由来の癌はまれで特に類内膜癌の報告は数例のみである。発生起源は腹膜中皮の後腹膜の陥入によるsecondary Mullerian systemとする仮説が現在有力である。

A 42-year-old woman presenting with left leg edema underwent ultrasonography and a pelvic mass was pointed out. CT showed that a left pelvic retroperitoneal mass caused stenosis of the left external iliac vein. On MRI, the mass was a multilocular cyst with enhancing solid component that showed restricted diffusion. The solid component showed a significant accumulation of FDG（SUV max＝23.6）. Operation was performed and pathological examination revealed endometrioid carcinoma. Since there were no abnormalities in the uterus, ovary or other parts, it was considered to originate from the retroperitoneum. Most of primary retroperitoneal cystic masses are benign, but with a solid part, we have to consider malignancy including mullerian carcinoma.