BEYOND MALIGNANCY: CA-125’S UNUSUAL MIMICS – A CASE REPORT ON CA-125 ELEVATION IN ADENOMYOSIS

Abstract

CA-125 is a widely recognized tumor marker, primarily associated with ovarian malignancies. However, its elevation is not exclusive to cancer and can be seen in benign conditions such as endometriosis, adenomyosis, and pelvic inflammatory disease. We present a case of a 47-year-old female with a three-month history of abdominal pain and heavy menstrual bleeding. Clinical examination revealed mild pallor, an anteverted uterus, and left forniceal fullness. Ultrasound findings showed a bulky uterus with multiple small fibroids and bilateral ovarian cysts. Laboratory investigations revealed an elevated CA-125 level (>1000 IU/mL), raising suspicion for malignancy. However, subsequent imaging with MRI and contrast-enhanced CT confirmed the presence of multiple heterogeneous myometrial lesions consistent with adenomyosis and non-enhancing simple bilateral adnexal cysts, likely paraovarian cysts. The patient underwent a total abdominal hysterectomy with bilateral salpingo-oophorectomy. Gross examination revealed an irregularly enlarged uterus with adenomyosis and simple serous paraovarian/paratubal cysts. Histopathological analysis confirmed adenomyosis and bilateral paratubal simple serous cysts. Cytology of peritoneal fluid was negative for malignancy. Postoperatively, the patient had an uneventful recovery, and repeat CA-125 levels decreased to 101 IU/mL. This case shows the importance of considering benign causes of CA-125 elevation to avoid misdiagnosis and unnecessary anxiety. Adenomyosis should be included in the differential diagnosis when evaluating elevated CA-125 levels, emphasizing the role of imaging and histopathology in establishing an accurate diagnosis.