Angiomyxoma is an infrequent tumor that originates from the mesenchyme and is primarily found in the female pelvic and perineal regions. Its diagnosis before surgery can be challenging due to its vague clinical manifestations and non-specific radiological features. One common symptom of this condition is painless swelling occurring around the pelvis and perineum. We report here a case study of a 36-year-old woman who complained of a large abdominal mass initially suspected to be retroperitoneal. The magnetic resonance imaging (MRI) results pointed towards a serous cystadenoma, while further examination during surgery suggested an initial possible diagnosis of degenerative fibroid. However, subsequent histopathological analysis confirmed that it was actually an angiomyxoma. It is crucial to consider aggressive angiomyxoma (AA) as one of the potential diagnoses for painless swellings in the genitofemoral region, particularly among women who are fertile and capable of reproduction. This particular case exemplifies the significance of including uncommon tumors like uterine angiomyxoma when making a differential diagnosis for pelvic masses, regular follow-up and monitoring for patients with a history of uterine masses, and the significance of histopathological examination to confirm the diagnosis of rare tumors.