A lump on the upper middle of the testicle may be an epididymal cyst. However, since it is present on both sides and since you feel that both side testicles are small, this may be a normal finding. On the other hand, may be you have low testosterone levels. Please consult your doctor. Take care!
The medical advice given should not be considered a substitute for medical care provided by a doctor who can examine you. The advice may not be completely correct for you as the doctor cannot examine you and does not know your complete medical history. Hence this reply to your post should only be considered as a guiding line and you must consult your doctor at the earliest for your medical problem.