Male toddler with a swollen right scrotum after having been taken cross country skiing in their parents baby backpack

US of testicular hematocele
Transverse US of the scrotum (above) shows the right scrotum to be larger in size than the left scrotum. Transverse (below left) and sagittal (below right) US of the right scrotum shows the right testicle to be intact, however it is surrounded by a complex septated fluid collection.

The diagnosis was testicular hematocele.