a localized tissue inflammation resulting in the formation of a ball-like collection of cells often referred to as a nodule. It can sometimes be felt as a hard lump underneath the surface of the skin. Doctors sometimes use the term "granuloma" loosely to mean "a small nodule," though this use of the term is not quite specific enough. Diagnosis of a small nodule as a granuloma requires surgical removal and examination by a pathologist.
Granulomas form when the immune system attempts to contain or “wall off” substances or particles that it perceives as foreign (and therefore, a threat) but is unable to eliminate. This immune system response can be caused by a variety of chemical, biological, and physical tissue irritants. Such substances can include materials such as keratin and vegetable particles as well as infectious organisms like bacteria and fungi.
As they pertain to cosmetic procedures, granulomas can result from the introduction of foreign materials such as injected dermal fillers, or of semi-solid implants used for soft-tissue augmentation. Granulomas have also been known to form around suture (stitches) fragments left behind in the tissue following surgery.
