All are differential diagnosis for acute scrotum except

In testicular malignancy, Usually, the patient presents with a painless testicular lump.A sensation of heaviness can occur if the testis is two or three times its normal size, but only a minority of patients experience pain.The hydatid of Morgagni (appendix testis) is a small embryological remnant at the upper pole of the testis. Can occasionally, undergo torsion, causing acute one-sided testicular pain. One-third of patients present with a palpable "blue dot" discoloration on the scrotum. (blue-dot sign)Ref: Bailey and Love 27e pg: 1507