Dark spots and discolorations on the penile shaft may not necessarily be precancerous although I agree that they warrant further evaluation. I suggest that you have this assessed by a dermatologist or urologist so that proper management be given if any intervention is indicated. Dark spots on the head or shaft of the penis may be due to abnormal structures like blood vessels .Another differential will be a nevus or moles.
How old are you?
For how long have you noted these discolorations on your penis?
Are these spots itchy?
Are they painful?
Is the color uniform or are there spots wherein the colors are lighter or darker in some areas?
I am 38
I noticed them today, not sure how long they have been there.
no pain involved
The bigger spots are darker the smaller ones are lighter
almost looks like blood blisters the shape seems to be round, nothing anywhere but the tip.. They are not open or seeping any fluid, even to the touch they are not sore.
I cant access your photo but based on what you have said it sounds like Genital Lentiginoses. Differential diagnosis does include fixed drug reaction, blue nevus, melanoma in situ and HPV-induced intrapithelal neoplasia. Caution should be taken to rule out a melanoma in situ, this is normally done via dermoscopy. I suggest you visit your GP.
Did you find out what these spots were, or see a doctor regarding that? I think I have exactly the same spots.