Testicular cancer

Testicular cancers are malignant tumors that form in one or both testes. They usually present as a mass that’s often detected in the early stages since they are on an organ that’s easily accessible during physical examination. Thus, they typically have a good prognosis.

The testes are a pair of male reproductive glands the size of small plums, that are located in the scrotum. The testes themselves are covered on the outside by the tunica albuginea, a white, fibrous layer.

If we slice a testis open and look inside, sorry for the cringe moment, we can see septa that partition each testis into lobules. Each lobule contains up to four seminiferous tubules, where sperm is synthesized.

Now let’s zoom in on a single seminiferous tubule, which is the “sperm factory”. A seminiferous tubule has a thick wall of epithelial cells that surround a fluid-filled lumen, a bit like a garden hose.

The wall of the tubule is made up of two kinds of cells: at the periphery, there’s the germ cells known as spermatogonia, which are the primordial sperm cells that begin dividing over and over in puberty, and give rise to male gametes.

Next to them are Sertoli cells which are large cells that extend from the margin all the way to the lumen of the tubule. Sertoli cells are supportive cells that provide nutrients to developing sperm cells, and contribute to the blood-testis barrier by only allowing certain molecules, like testosterone, into the seminiferous tubules.

Outside the tubule, there’s connective tissue with capillaries, as well as Leydig cells - another supportive cell which produces testosterone, which is a hormone necessary for the proper development of sperm.

During fetal development the entire body derives from three layers called germ layers; the ectoderm, mesoderm and endoderm.