Gumma

A gumma is a destructive granulomatous lesion characteristic of late syphilis. It can involve skin, bone or internal organs, producing local damage through a chronic inflammatory process. It belongs to gummatous syphilis, rather than being another name for the primary chancre. ^[ref]

The distinction illustrates how one infectious agent can produce different pathological patterns at different stages. A lesion's gross appearance, its microscopic inflammatory organization and evidence of the underlying infection are different observations. The category therefore describes a clinicopathological pattern, not a claim that every late syphilis presentation has the same anatomy or contains a readily visible organism.