A Rare Delayed Reaction to Filler: Granulomas Explained

A 2025 case report describes a woman who developed a firm lump in her cheek roughly nine years after hyaluronic acid filler, which turned out to be a granuloma, a walled-off inflammatory reaction to the product. It is a single case, and the authors stress that this reaction is very rare. Its main lesson for patients is simple: if you ever develop a new facial lump, tell your doctor about any filler you have had, even long ago.

Why this case was reported

Hyaluronic acid filler is designed to break down slowly in the body, and most people never have a problem beyond short-lived swelling or bruising. Because of that, a lump that appears years later is not something doctors or patients naturally connect to filler. Surgeons who see a facial mass may first think of a cyst, a salivary gland problem or a dental infection.

Case reports like this one are written to put an unusual possibility on clinicians' radar. They do not tell us how often something happens. They describe what one patient experienced, how the diagnosis was reached and what was done.

What the report describes

The patient was a 34-year-old woman seen by an oral and maxillofacial surgery team in Saudi Arabia. She had received cosmetic filler in both cheeks about ten years earlier. Around a year before her visit, a swelling began on the right side of her face and grew slowly.

On examination the lump was about 2 cm across, not tender and not draining. Her teeth were healthy, which ruled out a dental source, and the nerves of her face were working normally. Ultrasound showed an irregular pocket under the skin, and MRI confirmed injected material in both cheeks, with an abnormal collection on the right.

The surgeons removed the lump under general anaesthetic. Under the microscope, the tissue showed small pockets of hyaluronic acid surrounded by immune cells, including the large, fused "giant cells" that are the hallmark of a foreign-body granuloma. Some pockets had ruptured, which appeared to have triggered the reaction. The report does not describe her recovery or longer-term follow-up.

What is a granuloma, in plain terms?

A granuloma is the body's way of fencing off something it cannot easily clear. Immune cells gather around the material and gradually build a firm, organized cluster around it. The same process happens with splinters, some stitches and certain infections.

With filler, a granuloma is different from a simple lump of product sitting in the wrong place. A misplaced or overfilled area usually shows up soon after treatment and often responds to massage or to the dissolving enzyme hyaluronidase. A true granuloma is an active immune reaction, tends to appear months or years later, and can only be confirmed by looking at tissue under a microscope. You can read more about the different kinds of lumps in our article on delayed swelling and lumps after filler.

How strong is this evidence?

A single case report sits near the bottom of the evidence ladder. It is useful for describing what can happen, but it cannot tell us:

• how common the reaction is
• whether a particular product, technique or injection area raises the risk
• which treatment works most reliably
• why this patient reacted when most people do not

The report also leaves some gaps. The exact product and injection details from ten years earlier were not known, and follow-up after surgery was not described. These limits are normal for a case report, and the authors themselves frame granulomas as a very rare complication.

What it means for you

For most people, this case is reassuring in an odd way. It shows how unusual this reaction is, and that even years later there are clear steps to diagnose and treat it. It is not a reason to panic about filler you have had, and it is not a reason to avoid medical care if you notice a change.

A few practical points stand out:

• Keep a record. Write down when and where you had filler, the area treated, and the product type if you were told. This helps any future doctor.
• Mention old treatments. If you see a family doctor, dentist or surgeon about a facial lump, say that you have had filler, even a decade ago.
• Do not self-treat. Squeezing, massaging hard or using home remedies on a lump can make things worse.
• Get new lumps checked. Many facial lumps have nothing to do with filler. A medical assessment sorts out the cause.

Warning signs worth reporting

Contact your injector or family doctor promptly if a treated area develops a new, firm or growing lump, redness, warmth, tenderness, drainage, or swelling that keeps coming back. Seek urgent care for any skin colour change, blanching or severe pain soon after an injection, or any change in vision, because those can signal a problem with blood flow. Our article on vascular occlusion safety explains those early warning signs.

Questions to ask at your consultation

• What type of filler would be used, and can it be dissolved if needed?
• Will I receive written details of the product and amount used?
• What signs should prompt me to call after treatment, and who do I contact?
• Does my medical history, including past filler, change your advice?

Frequently asked questions

Can a granuloma really appear years after filler?

Yes, though it is rare. In this report the lump appeared roughly nine years after injection. Delayed reactions are thought to involve the immune system responding to remaining product, sometimes after a trigger elsewhere in the body.

Is surgery always needed?

No. This patient had the lump removed, but other cases are managed with medicines such as anti-inflammatory steroid injections or with hyaluronidase, depending on what tests show. Treatment is tailored to the individual and usually starts with the least invasive option.

Does this mean hyaluronic acid filler is unsafe?

No single case can show that. Hyaluronic acid filler has a long track record, and serious delayed reactions are uncommon. Like any medical treatment, it carries risks, which should be explained clearly before you decide.

If you have questions about past filler, a lump you have noticed, or whether filler is right for you, HealthPark Medical Aesthetics can talk through your history and options in a consultation, and refer you on if another cause needs to be ruled out.

Source

Almadan N, Althubaiti R, Uguru C, Pothanikat JJK, Alshamari JH. Exuberant delayed granulomatous reaction to hyaluronic acid filler material. Journal of Surgical Case Reports, 2025. Read the study