Primary adenomyoma of the fallopian tube mimicking tubal malignant tumor.

We report a rare case of adenomyoma localized only in the left fallopian tube mimicking tubal malignant tumor. A 45-year-old woman presented with mild pelvic pain, dysmenorrhea and left adnexal mass. Magnetic resonance imaging showed a solid tumor, suspected primary cancer of the fallopian tube, and serum carbohydrate antigen 125 was elevated to 72 U/mL (normal; 0-35). At surgery, the tumor was revealed as a left fallopian tube tumor without torsion. Postoperative histopathology showed that the tumor included bundle-like growing non-atypical leiomyoma cells and ectopic normal endometrium accompanied with endometrial stroma and we diagnosed primary adenomyoma of the left fallopian tube. Adenomyoma localized only in the fallopian tube is a rare entity and it can occur only in the fallopian tube.