Case Report: Giant vulvar aggressive angiomyxoma in a postmenopausal woman with a decade-long history

Background Aggressive angiomyxoma (AAM) is a rare, locally infiltrative mesenchymal tumor that typically arises in the pelvic-perineal region of reproductive-aged women. Its occurrence in postmenopausal women is uncommon and may present diagnostic challenges due to its indolent nature. Case presentation We report a case of a 63-year-old postmenopausal woman with a 10-year history of a gradually enlarging, asymptomatic right vulvar mass. Pelvic Magnetic Resonance Imaging (MRI) revealed a well-circumscribed, lobulated mass. Surgical excision was performed, and the gross specimen measured 15 × 8 × 6 cm. Histopathology confirmed the diagnosis of AAM, with an immunohistochemical profile showing Estrogen Receptor (ER) (+), Progesterone Receptor (PR) (–), and a Ki-67 proliferation index of approximately 10% in hotspot areas. All surgical margins were negative. Conclusion This case demonstrates that AAM can grow insidiously over many years in postmenopausal women, presenting as a large, asymptomatic mass. The atypical features, including a decade-long indolent history, PR negativity and a relatively elevated Ki-67 index, highlight the biological variability of AAM. However, the prognostic significance of these findings remains uncertain and requires further investigation. A high index of suspicion is necessary for vulvar masses with prolonged histories, even after menopause. As a single case report, this report has limited representativeness.