AUTHOR=Masuda Yuiko , Okabayashi Hiroko , Akaike Kimitaka , Hamada Shohei , Masunaga Aiko , Ichiyasu Hidenori , Ohashi Kenichi , Sakagami Takuro TITLE=Case Report: Tattoo sarcoidosis with epithelioid cell granuloma positive for Propionibacterium acnes JOURNAL=Frontiers in Medicine VOLUME=Volume 12 - 2025 YEAR=2025 URL=https://www.frontiersin.org/journals/medicine/articles/10.3389/fmed.2025.1552114 DOI=10.3389/fmed.2025.1552114 ISSN=2296-858X ABSTRACT=IntroductionTattoo sarcoidosis is characterized by a granulomatous reaction localized to the tattoo site and typical systemic symptoms of sarcoidosis. Herein, we report the case of a patient diagnosed with tattoo sarcoidosis.Case reportA 28-year-old man presented with subcutaneous nodules at two tattoo sites, bilateral hilar and mediastinal lymphadenopathy, multiple micronodules predominantly in the upper lobes of both lungs, elevated serum angiotensin-converting enzyme and soluble interleukin-2 receptor levels, hypercalcemia, and renal dysfunction. Skin biopsy of a subcutaneous nodule revealed epithelioid cell granulomas. Although periodic acid-Schiff, Grocott methenamine silver, and acid-fast staining showed negative results, antibody staining for Propionibacterium acnes within the epithelioid cell granuloma was positive. Remarkably, all lesions spontaneously resolved, and the systemic manifestations also improved without medical treatment.ConclusionThe pathogenesis of tattoo sarcoidosis remains unknown, although an immune response to tattoo pigments has been suspected. However, there is a theory that P. acnes is the causative agent of sarcoidosis. In the present case, the detection of P. acnes within the epithelioid cell granuloma suggests that the bacterium may play a role in the etiology of tattoo sarcoidosis.