Muscle weakness and myalgia as the initial presentation of serous ovarian carcinoma: a case report

INTRODUCTION: Epithelial ovarian cancer (EOC) has one of the worst prognoses among gynecologic cancers. An appropriate screening method is not available for EOC, and the initial symptoms such as abdominal pain or bloating, anorexia, and urinary urgency are vague. As a result, most cases of EOC are diagnosed at an advanced stage. CASE PRESENTATION: We report novel insights gained from the case of a 45-year-old, gravida 0, para 0 woman who presented to the emergency department with complaints of general weakness, fatigue, and myalgia over the previous two months. She reported progressive muscle weakness of the upper and lower extremities leading to difficulty walking. Serum muscle enzymes, such as creatine phosphokinase, were markedly elevated. No evidence of malignancy was detected upon imaging. A biopsy of the left vastus medialis muscle was performed, and the results were consistent with primary myopathy with myofibrillar disarray, suggesting paraneoplastic necrotizing myopathy. Explorative laparotomy was performed to evaluate these results, and histopathological analysis of the full specimen revealed a grade 3 ovarian serous adenocarcinoma with direct invasion to the rectum. CONCLUSIONS: Because of the lack of screening tools for EOC, any clinical findings suggesting its presence are valuable, and the possibility of EOC should be considered in unknown primary malignancies with initial complaints of muscle weakness or myalgia.