Mesotheleoma: did you mean mesothelioma?
Mesothelioma, which is commonly mispelled mesotheleoma, is a rare form of cancer affecting the linings of the lungs or abdomen. This lining, called the mesothelium, allows the organs to move against one another easily, allowing breath to move in and out of the lungs, or food to move through the colon. Surrounding the lungs and heart, the mesothelium is referred to as the pleura and pericardium. This serous membrane surrounding the abdomen is the peritoneum. It is from these names, the pleura and peritoneum, the pleura mesothelioma and peritoneal mesothelioma, respectively, get their names.
Mesothelioma (often mistakenly spelled "mesotheleoma") comes from the name of the mesothelium and "oma," meaning tumor. The mesothelium itself derivied it's name from "meso," meaning middle.
Mispellings such as "mesotheleoma" are not uncommon, as this disease is not widely known about; only two to three thousand cases are diagnosed in the US each year. This also, unfortunately, leads to cases of mesothelioma misdiagnosed or not diagnosed at all.
Other common mispellings include mesothilioma, mesothlioma, misothelioma, mesothileoma, mesotholoma, msothelioma, misothilioma, and mesotelioma.