My husband is 50 years old about 1.8  in height, weight about 100 kilos and has a history of angina, blood cancer treated successfully about a month and a half ago.  Two days ago he discovered a hard ball under his testicals.  Was sore when he closed his legs but the pain disappeared.
Hi and welcome to Chat Doctor.  I understand your concerns and I will try to help you as much as I can. Most such lumps are benign and may be just a cyst or lipoma. However, it would be good to do ultrasound to rule some more serious diseases out. Masturbation and intercourse should be avoided till pain persist, if possible since I may prolong inflammation course. Some more serious conditions such as tumors or torsion are rare but in doubtful cases you should do Doppler ultrasound or scenography. I hope I have answered you query. If you have any further questions you can contact us in every time. Kindly regards. Wish you a good health.