Sarcoidosis appearing in a tattoo

BACKGROUND: Sarcoidosis is a systemic disease that may present as tattoo granulomas. OBJECTIVE: A patient with systemic sarcoidosis who developed a granulomatous reaction within a tattoo is presented to stimulate interest in this unusual phenomenon. METHODS AND RESULTS: A patient with a 6-year history of pulmonary sarcoidosis developed sarcoidal granulomas restricted to one pigment of a tattoo. Previous reports of sarcoidal granulomas within tattoos are reviewed, and information about the pathogenesis of this process is explored. CONCLUSION: Sarcoid granulomas may develop in tattoos as an isolated local reaction or as the presenting sign of systemic sarcoidosis. The reaction itself may provide insight into further understanding the pathogenesis of sarcoidosis.