Spermatoceles and epididymal cysts are the most commonly encountered extratesticular cystic lesions. On ultrasound, they may be difficult to differentiate from one another as they both can present as thin-walled, well-defined anechoic lesions with posterior acoustic enhancement arising from the epididymis. Spermatoceles can be distinguished from epididymal cysts when the lesion demonstrates fine, low-level internal echoes with associated “falling snow” sign [1, 2]. The “falling snow” sign describes the movement of the low-level echoes within the spermatocele away from the transducer during power or color Doppler ultrasound evaluation (Fig. 1a, b), mimicking falling snow as can be seen in a snow globe (Fig. 2). High-intensity ultrasonic waves emitted by Doppler ultrasound mechanically move the particulate material within the lesion, a phenomenon known as acoustic streaming [3]. Acoustic streaming is not only encountered in spermatoceles but has also been described in other cystic lesions that contain low-level internal echoes, including ovarian cystic lesions, breast cysts, hydroceles, and cystic thyroid lesions [4].