Final answer:
Gummas, or granulomatous lesions, appear during the tertiary stage of syphilis, which is the last and most severe phase of the infection. It can result in considerable damage to multiple organs and may be fatal if left untreated.
Step-by-step explanation:
Gummas, which are granulomatous lesions, appear in the tertiary stage of syphilis. Tertiary syphilis can occur 10 to 20 years after the initial infection and is the final stage of the disease. This stage can cause severe damage to internal organs, including the brain and heart, and if not treated, it can lead to fatal outcomes. Gummas may develop on mucous membranes, bones, and internal organs, causing potentially massive tissue damage. They can result in destructive effects on the cardiovascular system, such as cardiovascular syphilis leading to a fatal aortic aneurysm or coronary stenosis, as well as severe damage to the central nervous system, leading to dementia, personality changes, seizures, and general paralysis.