The thing that comes to mind first would be hypogonadism. This essentially means that the testosterone level is low. This can be easily tested by measuring a testosterone level, LH and FSH - which as sex hormones that can affect testicular development.
Other considerations would be a semen analysis or biopsy - which would be the most definitive test.
Anatomical abnormalities in the testicle can be evaluated via an ultrasound.
If there is evidence of a low testosterone level, to my knowledge, this is not associated with testicular cancer.
I would discuss these options with your personal physician. An endocrinology referral may be considered.
Followup with your personal physician is essential.
This answer is not intended as and does not substitute for medical advice - the information presented is for patient education only. Please see your personal physician for further evaluation of your individual case.
Thanks,
Kevin, M.D.