卵巣粘液性癌に合併した卵巣微小嚢胞間質性腫瘍の1例

A case of ovarian microcystic stromal tumor accompanied by ovarian mucinous carcinoma

卵巣微小嚢胞間質性腫瘍はまれな腫瘍で，特に画像診断に関する報告は極めて少ない。今回我々は，前医で卵巣腫瘍を指摘され当院を受診した30代女性の症例で，左卵巣にT1強調像低信号，T2強調像で不均一な淡い低信号～高信号，中等度の拡散制限を示し，ダイナミック造影MRIで早期から後期まで強く濃染される充実性腫瘤を認めた。充実性腫瘤については明らかな質的診断に至らなかったが，左卵巣に併存していた別の病変について悪性腫瘍を疑ったため，審査腹腔鏡および左卵管卵巣切除術を行ったところ，病理組織学的に充実性腫瘤は卵巣微小嚢胞間質性腫瘍と診断したことから，その画像所見を中心に報告する。

We report the case of a woman in her 30s with ovarian microcystic stromal tumor accompanied by ovarian mucinous carcinoma. Many of the previous reports of ovarian microcystic stromal tumor suggest a large pelvic mass with a dominant cystic component and a peripheral solid component with a mild degree of vascularity. Our case showed a solid component which didn’t have a cystic part. MRI showed low signal intensity on T1-weighted images, heterogeneous signal on T2-weighted images, hyperintensities on diffusion-weighted sequences and intense enhancement from in the early phase to in the later phase of dynamic MRI. To our knowledge, this is one of the first reports of the rare radiologic findings of ovarian microcystic stromal tumor.