**Core Concept:** Tuberculosis (TB) is an infectious disease caused by the bacteria Mycobacterium tuberculosis, which primarily affects the lungs (pulmonary TB). However, it can also involve other organs, including the genitourinary system. Tuberculosis of scrotal contents refers to the involvement of scrotal organs (testes, epididymis, and spermatic cord) due to the spread of infection from the lungs or via lymphatic route.

**Why the Correct Answer is Right:** In tuberculosis of scrotal contents, the first organ to get affected is the epididymis. The epididymis is a coiled tubule that runs along the spermatic cord and stores and matures sperm. The epididymis is relatively close to the testes and is an early site of involvement in scrotal TB due to its proximity to the primary site of infection (lungs) and the potential spread via the lymphatic system.

**Why Each Wrong Option is Incorrect:**

A. Testes: Although the testes can be involved in advanced cases, they are usually the last organ to be affected due to their deep location within the scrotum.

B. Spermatic cord: The spermatic cord contains the reproductive vessels and nerves, but it is not the primary site of infection in tuberculosis of scrotal contents.

C. Scrotum: The scrotum is a secondary site of involvement, after the epididymis, as it becomes inflamed and swollen due to the spread of TB.

D. Skin: The skin is the outermost layer and is not the primary site of involvement in tuberculosis of scrotal contents.

**Clinical Pearl:** Recognizing the first organ to be affected in tuberculosis of scrotal contents is essential as it guides the clinician to suspect the possibility of scrotal TB, particularly when dealing with a patient from an endemic area. This clinical suspicion can lead to appropriate investigations and timely management, including antituberculosis therapy, to prevent progression of the disease and prevent complications like hydrocele formation and testicular atrophy.