An Asymptomatic Case of Mullerian Adenosarcoma following Tamoxifen Use

Mullerian adenosarcomas are rare: approximately 200 cases have been reported. This tumor usually occurs in peri/postmenopausal women and asymptomatic case is rarely reported. Use of tamoxifen has been considered to have some association with the occurrence of this tumor. We here report a woman after tamoxifen administration who suffered Mullerian adenosarcoma of the uterine body, but was asymptomatic. We wish to emphasize the importance of recognizing this tumor for both gynecologists and pathologists. A 62-year-old woman was incidentally diagnosed with a possibly malignant uterine mass on PET scan. She had a history of right breast cancer 9-year back, for which surgery+chemotherapy was done. Tamoxifen was administered for 5 years after the chemotherapy. PET scan for follow up revealed heterogeneously mass in uterine body with no lymph swelling. Ultrasound revealed a large heteroechoic mass in the uterine body. Total abdominal hysterectomy with bilateral salphingooophoectomy was done. Histological examination confirmed the diagnosis of mullerian adenosarcoma. Post-operative course was uneventful and radiotherapy is planned. Uterine adenosarcoma has variable survival rate depending on its sarcomatous component, lympho-invasion, and myoinvasion. This patient showed no lymph invasion and less myoinvasion, which may account for her good prognosis. Physicians should be aware that this tumor can occur in patients with history of tamoxifen use.