術前診断が困難であった脾サルコイドーシス症に対して腹腔鏡下脾臓摘出術を施行した1例

Laparoscopic splenectomy for the differential diagnosis of multiple nodules of the spleen : a case report

◆要旨：患者は77歳，女性．自覚症状は特に認めず，偶然撮影した胸・腹部CTで脾腫と脾内多発低吸収性腫瘤を指摘され，FDG-PETでは脾臓内不均一高集積を認めた．脾原発悪性リンパ腫が疑われ，確定診断を目的に腹腔鏡下脾摘出術を施行した．摘出標本は最大径2cmまでの境界明瞭な白色充実性結節が多数存在し，病理組織学的には非乾酪性類上皮細胞肉芽腫を形成し，内部にラングハンス型巨細胞を認め，脾サルコイドーシス症と診断された．脾臓の多発結節性病変は画像上では脾サルコイドーシス症と脾臓悪性腫瘍との鑑別は困難であり，確定診断の方法として低侵襲な腹腔鏡下手術も選択肢の1つになり得ると考えられた．

　A 77-year-old woman was incidentally found to have multiple small nodules in the spleen on CT scan. The mediastinal and abdominal lymph nodes enlargement were also detected. Positron emission tomography with fluorine-18 fluorodeoxyglucose（FDG）showed high FDG accumulation in the splenic lesions as well as in the mediastinal lymph nodes. These findings suggested the possibility of malignant lymphoma. Laparoscopic splenectomy was carried out to obtain the histopathological diagnosis. Histologically, multiple noncaseating epithelioid granulomas with multinuclear giant cells were seen in the splenic nodules which were diagnosed as splenic sarcoidosis. It is very difficult to reach the definitive diagnosis of the splenic multiple small nodules only by imaging. As in this case, we think laparoscopic splenectomy is a useful and minimally invasive maneuvers for the differential diagnosis of the splenic nodules.