Although, all lumps found on testicles, require further examination like ultrasound, not all lumps on the testicles are tumors, and not all tumors are malignant.
Testicular cancer, indeed, can cause testicle pain and discomfort, but, it is well known clinical fact that only a small percentage of testicular cancers are painful from the outset.
At the upper part of the testicle, or at the back of the testicle, is a structure known as epididymitis, where the sperm is matured and stored.
It is possible that the lump you've felt is a spermatic cyst located at the head of epididymitis or epididymal cyst.
This is usually painless, but, sometimes it can be manifested as painful lump.
Have you noticed some redness on your left testicle?
Do you feel pain when urinating and ejaculating?
