Why does this lump on my testicle appear and disappear?

Dear Ask The Doctor: Hi there, My boyfriend just told me that he has a lump underneath his testicles and also he periodically suffers from sharp pains in his lower belly. He said he's had the lump 5years ago too but that it comes and goes...He refuses to go to the doctor but I am worried it might be testicular cancer. What would be your opinion? Could it just be an infection? Looking forward to yuor answer, Jen

It is possible he has a hernia and he should see a doctor as soon as possible because he may need surgery. The pelvic organs are separated from the abdominal organs by certain structures. Defects or weak points in these structures may cause abdominal organs to herniate (protrude into) the pelvic area. The intestine is the most common organ that herniates into the inguinal area (groin) or the testicles. At first, the intestines will be reducible (spontaneously scopes into the testicle then goes back to original position). This probably explains why he has occasional abdominal pains and the lump comes and goes. However, if this is not corrected, it always has a potential to get incarcerated (intestine protrudes into the testicle but can’t go back to original position because it is swollen) and this will need surgery urgently. This will also involve a longer hospital stay and recovery time, and it may have complications too. Most doctors would recommend elective (scheduled) surgery since it usually involves much shorter hospital stay and recovery time, and most importantly, it also eliminates the potential of the hernia getting incarcerated. If what he has is not a hernia, it is still worth checking. Testicular cancer is also a consideration but usually, it presents as a painless mass inside the testicles. In general, it has a fair prognosis and curable even when diagnosed at terminal stage. There are a number of other conditions that will have a lump on the testicle (varicocele, hydrocele) but he will need to have it checked by a doctor to make sure it is not serious and appropriate interventions can be done. Some conditions involving the testicles will also adversely affect a man’s fertility status if interventions are not done in time. A simple physical exam by a doctor can already tell a lot of things. I do hope I have appeased your concerns and you can convince your boyfriend to see a doctor very soon. Take care always.