Challenging diagnoses in a case report: Ovarian fibrothecoma with elevated CA125 levels mimicking malignancy

Ovarian fibromas are benign tumours arising from the connective tissue of the ovarian cortex, classified into three pathological subtypes: fibroma, thecoma, and fibrothecoma. Their diagnosis is complicated by their solid nature and potential association with ascites and pleural effusion, resembling Meigs syndrome. Elevated serum CA125 levels can further complicate differentiation from malignant ovarian epithelial tumours.

A 37-year-old female from a rural area presented with a distended abdomen and weight loss lasting 2 months. Clinical examinations revealed a solid pelvic mass and diagnostic tests showed significantly elevated CA125 levels. Imaging suggested a large ovarian mass and surgical intervention confirmed a fibrothecoma of the left ovary. The postoperative course was uneventful, with subsequent resolution of ascites and pleurisy.

The diagnosis of ovarian fibromas/fibrothecomas poses challenges due to their asymptomatic nature, solid appearance, and occasional association with the Meigs syndrome. Elevated CA125 levels can mislead the diagnosis of epithelial ovarian carcinoma. The case underscores the importance of considering ovarian fibromas/fibrothecomas in the differential diagnosis of ovarian tumours with elevated CA125 levels, especially in women of reproductive age. The benign nature of these tumours necessitates a conservative surgical approach, emphasizing the importance of intraoperative frozen section analysis.

Ovarian fibrothecomas associated with elevated serum CA125 levels are rare. Their presentation can mimic malignant ovarian neoplasms, leading to potential diagnostic confusion. Surgical removal remains the treatment of choice, with a favorable prognosis post-surgery.