This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Urology, Subject name: Surgery
A 20 year old male presents with scrotal mass. The first investigation to be done is 
Select and explain. 
A. Clinical evaluation (Palpation and transillumination), B. USG, C. Biopsy, D. AFP
A: Clinical evaluation (Palpation and transillumination)
Answer: A: Clinical evaluation (Palpation and transillumination) 
Explanation: Differential diagnosis are hydrocele, hematocele, epididymal cyst, spermatocele, varicocele, inguinal hernia, testicular tumours . Thus clinical examination should be done first to differentiate between them.