With the light test, the doctor is looking for varicoceles (i.e. the vein clumps). However, with any scrotal mass, I would consider a scrotal ultrasound which can more thoroughly evaluate for any masses, include cysts, varicoceles, or cancer. If you still have the symptoms, this approach should be considered.
You can also consider a urology referral, although any primary care physician can order the ultrasound.
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.