Cosmetic Filler and PET Positivity: The Risk of a False Positive.

[OBJECTIVE] To discuss a case of hyaluronic acid filler displaying as PET avid resulting in a false positive for local recurrence and review of the literature of how filler presents on PET.

[STUDY DESIGN] Case report and literature review.

[METHODS] Retrospective case review of a patient with angiosarcoma with PET-MRI positivity after hyaluronic acid filler injection. Review of the literature was performed.

[RESULTS] A 49-year-old female with low grade angiosarcoma of the right cheek pT1N0M0 was treated with wide local excision and staged reconstruction with cervicofacial advancement flap with subsequent adjuvant radiation therapy. Surveillance PET/MRI scans were conducted every 3 months. After one year without recurrence, HA injectable filler was offered to correct resultant right facial soft tissue defect. The patient proceeded with HA filler and was counseled on the risk of local increased SUV on imaging. Her PET/MRI 3 months later revealed postsurgical changes in the right premaxillary soft tissues with associated low-grade hypermetabolism with max SUV 1.8, which elevated from prior max SUV 0.9. Contralateral left maxillary soft tissues revealed max SUV 0.8. Biopsy was initially favored for concern of local recurrence until the potential for filler to be associated with elevated SUV was discussed. Further evaluation with MRI showed diffusely increased T2 signal with some trace enhancement in the region of PET activity, confirming that findings were consistent with HA filler augmentation per the neuroradiologist team.

[CONCLUSIONS] Fillers, including hyaluronic acid, are associated with elevated SUV on PET-CT. Otolaryngologists should be aware of these features to improve patient counseling, avoid unnecessary procedures, and reduce patient anxiety. Laryngoscope, 133:2951-2953, 2023.