A 28-year-old male presents with a dull, heavy dragging sensation in his left scrotum. On physical examination, the left hemiscrotum reveals a collec…

A left varicocele is common due to the anatomical drainage of the left testicular vein into the left renal vein at a 90-degree angle. However, a sudden-onset varicocele that does not empty in the supine position, or a right-sided varicocele, should raise suspicion for an retroperitoneal mass such as a renal cell carcinoma invading the renal vein. In young adults, bilateral or left varicocele is typically idiopathic, but secondary causes must be considered if atypical.