A suture granuloma is a small mass comprised of clustered immune cells that may develop around the site of a surgical procedure. It is a potential complication of surgery that can be an increased risk in certain cases, as some types of sutures appear to promote granuloma formation. In a patient with a history of surgeries, small masses must be evaluated with care to differentiate between benign and malignant growths, and it may be necessary to perform a biopsy to determine what kinds of cells are involved.

In the case of a suture granuloma, the immune cells cluster to create a wall between the rest of the body and a foreign object. The immune system may determine that sutures, staples, fixators, and other surgical devices are dangerous, and can use scarification and clumps of immune cells to isolate these materials. This can create the appearance of a lump at the suture site. The lump may protrude from the skin and can appear red and irritated in some cases.

Sometimes a suture granuloma develops shortly after surgery, while in other cases it may develop in the long term in response to the irritation caused by staples and permanent sutures. The patient may be concerned by the appearance of the lump and may report it to a doctor. An evaluation can include a quick palpation, a discussion of the patient's history, and a needle aspiration biopsy to find out what kinds of cells are involved.

If the growth is a simple suture granuloma, the doctor may not recommend any treatment. In cases where the growth impedes movement or causes a cosmetic problem, it can be removed. After removal, the surgeon can recontour the skin to remove any lumps or dips, and may recommend the use of compression bandages and other tools to limit the development of another lump. Sometimes, however, the suture granuloma may become recurrent, and it could create a lifelong problem for the patient.

Patients should monitor their surgical sites carefully for issues like heat, swelling, changes in skin color or texture, and strange growths. Surgeons prefer to err on the side of caution and can examine a patient with concerns about anything occurring at the site of an incision. Since a suture granuloma can mimic a more invasive growth, and vice versa, it may be important to accurately diagnose the growth with the assistance of a biopsy to determine whether it is a risk.