Malignant mesothelioma is a fast-growing and swift-spreading form of cancer caused by the interplay between long-term exposure to a carcinogen—most commonly associated with asbestos—and genetic predisposition. This is the reason that 50 people may work the same number of years in a factory that produces asbestos-containing materials without sufficient safety measures in place and of those, only 40 wind up diagnosed with mesothelioma later in life. The role of genetics in mesothelioma development is a topic of much research, with the hope that pinpointing the genes that contribute to mesothelioma can help researchers to pinpoint the key to bringing the cancer to a halt.

What is paratesticular mesothelioma?

Paratesticular mesothelioma is the type of mesothelioma that afflicts the lining of the testicles. The testes are encapsulated by a lining called the mesothelium, and when mesothelioma occurs, that lining is invaded by cancer cells, causing a tumor to develop.

The rarest form of an already-rare disease

Paratesticular mesothelioma is by far the most rare form of mesothelioma, afflicting less than 1 percent of all mesothelioma victims, with fewer than 500 cases worldwide. With so little data available, paratesticular mesothelioma remains, in large part, a mystery, as widespread data regarding symptoms and genetic predisposition are simply not available at this time.


Symptoms have varied widely across the few cases diagnosed thus far, but most had a visible lump where the tumor was located that could be seen when viewing the scrotum. Some patients experienced pain in the tumor site, whereas others experienced no pain and would not have noticed the tumor until it grew to such size as to cause a visible lump.


Treatment for paratesticular mesothelioma involves surgery, generally surgical removal of the afflicted testis and its surrounding tissues. This treatment methodology has proved successful thus far, with survival rates reaching far beyond those of other forms of mesothelioma, and recurrence rates at a minimum. More research is called for in order to draw broader conclusions, but the outcomes of the limited number of paratesticular mesothelioma victims thus far have been promising.