Granuloma

An aggregation of cells of a type associated with chronic inflammation. They usually occur as a reaction to certain infections, such as tuberculosis, or a foreign body, such as a suture, but they may develop for unknown reasons in conditions such as sarcoidosis. A pyogenic granuloma is an excess of granulation tissue developing at the site of an injury to the skin or mucous membrane. (See also granuloma annulare; granuloma inguinale.)