This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: General surgery, Subject name: Surgery
All are differential diagnosis for acute scrotum except 
Select and explain. 
A. Epididymitis, B. Hydatid torsion, C. Testicular torsion, D. Testicular cancer
D: Testicular cancer
Answer: D: Testicular cancer 
Explanation: 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