術前に右傍卵巣嚢腫と鑑別が困難であった低異型度虫垂粘液性腫瘍と虫垂カルチノイド腫瘍による虫垂重複腫瘍の1症例－超音波断層法の重要性－

抄録

  Preoperative diagnosis mainly including presumptive pathological diagnosis on adnexal tumors has various issues such as differentiation from tumors of other adjacent organs. We experienced a case of appendix tumor after diagnosis as right ovarian cyst at this time. Further, this case had a very rare condition with a simultaneous appendix tumor of low-grade appendiceal mucinous tumor and appendiceal carcinoid tumor, and is reported by adding bibliographic consideration.

  This case was a 24-year-old female with no experience of sexual intercourse. CT identified a 6cm-long cyst in the pelvis at the time of admission for Campylobacter enteritis; therefore she was referred to the department of gynecology with the diagnosis of a right ovarian cyst. A normal right ovary was confirmed as a result of MRI, leading to diagnosis of relatively frequent right ovarian cyst. However, transrectal ultrasound tomography presented a layered echo image that was different from echo images common to paraovarian cysts. Since the diameter of the tumor also increased, laparoscopic operation was performed, leading to the finding of appendix tumor.

  Only six cases of simultaneous appendix tumor including this case were confirmed in Japan, and this is the first case reported by a gynecologist. When this case was verified on the basis of literature of appendix tumor that was preoperatively diagnosed as ovarian tumor, the layered echo image from ultrasound tomography seems to reflect high viscosity of the content solution, and does not match the tumor image of a clear boundary with a low signal in T1 weighted imaging and a high signal in T2 weighted imaging of MRI. This difference is important to differential diagnosis and can be helpful for diagnosis. If layered echo images are visualized in the process of preoperative examination of adnexal tumors, appendix tumor needs to be remembered for differential diagnosis although frequency is low.