A gumma is a form of granuloma.

Syphilitic gummas are seen in benign tertiary syphilis. Though they don't always develop, they occur singly, in groups, or exhibit a diffuse distribution. Gummas have a firm center that may become partly hyalinized. These central portions exhibit coagulative necrosis, though they also retain some of the structural characteristics of previously normal tissues. Other histological features of gummas include an intervening zone of epithelioid cells with indistinct borders and multinucleated giant cells, and a peripheral zone of fibroblasts and capillaries. Lymphocyte and plasma cell infiltration can be seen in the peripheral zone as well. With time, gummas eventually undergo fibrous degeneration, leaving behind an irregular scar or a round, fibrous nodule.

-- we need more information about this. There are other sorts of gumma, it appears...

External links

• http://www.medstudents.com.br/wwwboard/previous/case3/syphilis.htm
• http://www.nlm.nih.gov/medlineplus/ency/article/000859.htm

Gumma is an alternate spelling for the Gunma Prefecture in Japan.