If untreated, various types of cancer can cause the development of necrotic lesions — that is, dead, rotting tissue — that give off a powerful odor. For instance, a man who suffered from an undiagnosed cancer in his penis developed such a powerful stink that his office colleagues refused to work with him – which was the only reason he sought medical help. His doctor hypothesized that some substance was being drawn from the necrotic lesion and released through the sweat glands [source: Liddell].
Another patient with psychosis had such a bad body odor that her psychiatrist could smell her even before she got to his office. "It turned out that this poor lady had advanced breast cancer, with a lesion that was eating through the breast and oozing foul-smelling necrotic gunk," the doctor wrote. "She was too psychotic to know what was happening." But after the psychiatrist got her to have cancer surgery and put her on antipsychotic medication, both the odor and her mental confusion subsided [source: Cohen].