A gumma is a soft, tumor-like growth of the tissues (granuloma).

Causes

A gumma is caused by syphilis. It appears during late-stage tertiary syphilis. It usually contains a mass of dead and swollen fiber-like tissue, and occurs most often in the liver. It also can occur in the:

• Bone
• Brain
• Heart
• Skin
• Testis
• Eyes

Similar-looking sores sometimes occur with tuberculosis.