胸腺腫の脾臓転移に対し腹腔鏡下脾部分切除術を施行した1例

A case of laparoscopic partial splenectomy for a splenic metastasis of thymoma

◆要旨：症例は64歳，男性．5年前にB1型胸腺腫，正岡分類Ⅲ期にて胸腺全摘，左腕頭静脈，左横隔神経，心膜合併切除，3年前に胸腺腫の両側胸膜播種再発し，胸腔鏡下胸膜剝離術を施行された．その後，胸膜播種再発，肺転移を認め化学療法を施行され，経過観察されていた．定期のCT検査で，脾臓に40mm大の造影効果を伴う充実性腫瘤を指摘され，診断・治療目的に腹腔鏡下脾部分切除術を施行した．手術は砕石位で施行し，脾門部で腫瘍を含む脾臓下極側へ流入する血管を切離した．脾実質はdemarcation lineに沿って，超音波凝固切開装置にて破砕法で離断し，脾臓を部分切除した．病理組織検査にて胸腺腫の脾臓転移と診断し，現在，外来で化学療法を継続中である．胸腺腫の脾臓転移に対し腹腔鏡下脾摘出術を施行した1例を経験したので報告する．

　A 64-year-old man had a thymectomy for type B1 thymoma and Masaoka's stage Ⅲ, five years ago. A follow-up CT scan revealed a 4-cm solid mass with contrast enhancement in his spleen. A laparoscopic partial splenectomy was performed for diagnosis and treatment. The operation was performed in the lithotomy position, and the blood vessels flowing to the lower pole of the spleen containing the tumor were cut at the splenic hilum. The splenic parenchyma was cut along the demarcation line by clamp crushing method using an energy device, and the spleen was partially excised. His tumor was diagnosed as splenic metastasis of thymoma by histopathological examination and he is currently undergoing chemotherapy as an outpatient. Splenic metastasis of thymoma is a very rare case. Laparoscopic partial splenectomy was an effective treatment for this case.