Solution: Adenomatoid tumors are uncommon neoplasms of the paratesticular tissues, probably of mesothelial origin. The usually involve the epididymis and are primarily evaluated with US. It is a benign growth, but is usually excised surgically. It is usually not intra-testicular, but can be. As opposed to intra-testicular masses, extra-testicular masses are generally benign, but do realize that several studies have shown that up to 15-20% of extra-testicular masses end up being malignant, so be aware of the fact that extra-testicular masses are not always benign.