Cancer Research UK says possible signs of testicular cancer include:
A lump in the testicle - although most testicular lumps aren’t cancerous, and the charity estimates that fewer than four in every 100 are cancer.
A cancerous lump isn’t usually painful, and can be as small as a pea, or may be much larger.
A dull ache in the affected testicle, or in the lower abdomen.
Heavy feeling in the scrotum.
Possible growth or tenderness of male breasts, due to hormones produced by the cancer.