agree that this card is confusing. will need some help figuring out if it is correct.
confusing concept but i think primary/idiopathic is most commonly left sided (85%) due to insertion angle to left renal and hydrostatics of the left testicular vein. IVC compression due to a mass (renal cell carcinoma) or obstruction from a thrombus may also cause varicocele, and although it may be either side the board questions like to make it right sided as that side is less likely primary/idiopathic (source: AMBOSS library)
this card sucks bc it can be either side and left is more common and amboss confirms all this, going to change cloze to reflect right-sided should make you think mass causes and add amboss stuff to extras
very likely this needs revisited but will approve and clear queue for now