I'm in stage 3.8 according to the calculator, but my testes are still small; they're about 2.9 cm in length I have some armpit hairs, and the hairs around my groin are dense, spreading up and down. I have a varicocele on my left testes. Could this be the cause of my small testes? My penis is quite normal.
Your testicles are where they should be for someone who is in stage 3 of development.
A varicocele is when some of the values in your scrotal veins fail. The values are to keep blood from pooling in lower areas of the body. A man with a varicocele has veins in his scrotum that are swollen. It is often described as feeling like a bag of worms in the scrotum. Often varicocele cause no harm. Varicoceles are not treated unless there is pain or discomfort, or there is indication that it is making a male infertile. The infertility is suspected to be caused by the pooling blood keeping the testicles too warm.
There are cases where a varicocele does cause the testicles not to develop as large as they should be. Treatment of the varicocele in a teenager does allow the testicle to catch back up in its growth.
In order to find out if you need treatment, you need to see an urologist. Among the tests he will do, he will ask for a sample of your semen. He will examine it under a microscope to see how many viable (healthy) sperm are present. If it looks like the varicocele is making you infertile, he will suggest surgery to correct the problem. The surgery is a relatively easy one that does not require hospitalization.
There is an excellent write-up on varicoceles at Medscape. It is full of medical jargon, but if you need any of it explained, just let me know.