Successful diagnosis of an occult fallopian tube carcinoma detected from the diaphragm metastasis.

We herein reported a rare case of an occult fallopian tube carcinoma first detected from the diaphragm metastasis. An 83-year-old woman who had a 30-mm tumor on the right diaphragm underwent radical resection. Pathologically, the tumor was diagnosed as a high-grade serous adenocarcinoma, suggesting metastasis from the pelvic visceral carcinoma. Although the primary site could not be detected by imaging examinations, laparoscopy revealed multiple peritoneal disseminations; therefore, total hysterectomy was performed. Finally, microscopic tumor invasion into the right fimbriae of the fallopian tube was found. A precise and detailed pathological and immunohistochemical examinations of the resected metastatic diaphragm tumor helped us obtain a proper diagnosis of the primary lesion and treat the patient appropriately. Since it is difficult to diagnose diaphragm tumors before surgery based on the anatomy, surgical options have played an important role in their treatment and diagnosis clinically.