A 6-month-old boy presented with right scrotal swelling since birth. It was soft and fluctuant with a positive transillumination test. Gray-scale US showed a multicystic extratesticular, extraepididymal mass in the right hemiscrotum (arrow), with moving internal echoes (Fig. 1). The septae showed flow on color Doppler (Fig. 2). Findings were suspicious for scrotal lymphatic malformation, confirmed on surgery. Lymphatic malformations are congenital lymphatic hamartomas. Ninety percent occur before 2 years of age and 95% occur in the neck or axilla. The scrotum is an uncommon site, and it may be misdiagnosed as hernia, hydrocele, varicocele, or epididymal cysts, resulting in improper treatment and recurrence [1]. It is typically separate from testis and epididymis. Internal echoes in the cysts are caused by hemorrhage and debris. The presence of arterial flow within the septae is a finding that would not be expected in an organized pyocele or hematocele, which may have similar appearance. Rhabdomyosarcoma is another differential diagnosis, but that appears as a complex solid-cystic mass [2].

Fig. 1
figure 1

Gray-scale US

Full size image
Fig. 2
figure 2

Color Doppler

Full size image