**Core Concept**
A trans-scrotal biopsy is contraindicated in cases of suspected testicular cancer due to the increased risk of tumor spillage and recurrence. The correct approach is to perform a radical orchiectomy through an inguinal incision to remove the tumor en bloc.

**Why the Correct Answer is Right**
The primary concern in a patient presenting with painless testicular swelling, fever, and weight loss is testicular cancer. A trans-scrotal biopsy would compromise the integrity of the tumor and increase the risk of local recurrence. In contrast, an inguinal orchiectomy allows for the removal of the tumor with a margin of normal tissue, reducing the risk of recurrence. Furthermore, an inguinal approach preserves the scrotal skin and reduces the risk of wound complications.

**Why Each Wrong Option is Incorrect**
**Option A:** USG scrotum is indicated in this patient as it helps in evaluating the testicular mass, assessing for any scrotal or testicular pathology, and guiding further management.

**Option B:** CT abdomen and pelvis is also indicated as it helps in staging the cancer, identifying any metastases or retroperitoneal lymphadenopathy, and guiding further management.

**Option C:** Chest x-ray is indicated in this patient as it helps in detecting any pulmonary metastases or mediastinal involvement.

**Clinical Pearl / High-Yield Fact**
In cases of suspected testicular cancer, a radical orchiectomy through an inguinal incision is the preferred approach to remove the tumor en bloc and reduce the risk of recurrence.

**Correct Answer:**
✓ Correct Answer: D. Trans-scrotal biopsy.