Sonographic appearance of aggressive angiomyxoma of the scrotum

Aggressive angiomyxoma (AAM) is a rare, locally infiltrative tumor that occurs almost exclusively in the pelvic and perineal regions of women of childbearing age. We report the unusual case of a 26-year-old man with an AAM presenting as a slowly enlarging scrotal mass. Gray-scale scrotal sonography demonstrated a well-demarcated, hypoechoic, extratesticular, extraepididymal mass with multiple thin, echogenic internal septa. The mass arose inferior to the left testicle and displaced the testicle cephalad. Color Doppler sonography revealed surrounding vascularity but no Doppler signals within the mass. The testicles and epididymides demonstrated normal echogenicity and vascularity. Histologic examination of the excised mass revealed a well-demarcated, nonencapsulated lesion composed of spindle-shaped cells in a myxoid background with a prominent vascular component.