Case Report: Pelvic–perineal deep angiomyxoma presenting as hematoma-like paravaginal masses: a report of two cases

Deep angiomyxoma (DAM) is a rare, locally infiltrative mesenchymal tumor of the female pelvic and perineal regions that is often misdiagnosed because of nonspecific clinical and ultrasonographic findings. We report two cases of pelvic–perineal DAM initially interpreted as paravaginal hematomas. One patient underwent ultrasound-guided aspiration and thrombin injection before progressive enlargement prompted further evaluation. Magnetic resonance imaging (MRI) demonstrated marked T2 hyperintensity, internal swirling structures, and extension along pelvic floor tissue planes, raising suspicion of DAM. Both patients underwent surgical resection with histologically negative margins (R0). Histopathology confirmed DAM with estrogen receptor and progesterone receptor positivity. Following multidisciplinary discussion, both patients received six cycles of individualized postoperative gonadotropin-releasing hormone agonist therapy. No radiological recurrence was observed at 11 and 12 months, respectively. Persistent or enlarging hematoma-like pelvic–perineal masses without a clear precipitating factor should prompt consideration of DAM and further MRI evaluation. MRI is useful for suggesting DAM and delineating tumor extent, whereas definitive diagnosis relies on histopathology. The benefit of routine postoperative endocrine therapy after R0 resection remains uncertain.