The most common sign of testicular cancer is a painless lump in your testicle. Other symptoms include: Swelling or sudden fluid build-up in your scrotum. A lump or swelling in either testicle. A feeling of heaviness in your scrotum. Dull ache in your groin or lower abdomen. Pain or discomfort in your scrotum or a testicle. A shrinking testicle (testicular atrophy). These symptoms can occur with other conditions, too, so don’t panic if you notice them. Still, schedule a visit with your provider to be sure. Delays in diagnosis allow cancer cells time to spread, making the disease harder to treat.