Proliferating trichilemmal cyst is considered as a rare tumor that originates in the outer root sheath of hair follicle. Metastatic potential has not been yet fully established. Moreover, histological analysis does not allow precise malignancy prediction. Proliferating trichilemmal cyst glucose metabolism behavior was never previously described. Herein, we report the case of a 62-year-old patient with a left shoulder proliferating trichilemmal cyst showing an intense uptake of ¹⁸F-FDG on PET/CT examination. ¹⁸F-FDG PET/CT could be proposed to optimize diagnostic strategy of patients with proliferating trichilemmal cysts.