Tattoos causing local and even generalized lymphadenopathies including sarcoidosis.

Tattooing deposits ink into the dermis comprising an immunologically highly active organ that filters foreign antigens via lymphatic drainage towards regional lymph nodes. Given chronic antigenic stimulation upon dermal tattoo pigment deposition, lymphadenopathies might manifest both locally and even generalized as granulomatous inflammatory morbidities including sarcoidosis but might not be considered as tattoo-related differential diagnosis. This prompted us to summarize recent evidence on tattoo-associated lymphadenopathies by analyzing clinical presentation, localization, diagnostic workup including histopathology, treatment, and outcomes in a systemic literature survey. The included publications revealed that local lymphadenopathies consistently showed pigment-laden macrophages in draining lymph nodes without granuloma formation, supporting passive lymphatic transport. Conversely, generalized tattoo-associated lymphadenopathy cases predominantly involved hilar or mediastinal lymph nodes particularly observed in sarcoidosis patients, often with granulomatous changes in lymph nodes and/or tattooed skin. In several reports, the disease onset followed immune-modulating events such as laser tattoo removal, immune checkpoint inhibitor therapy, or vaccination. Importantly, affected lymph nodes frequently demonstrated avidity in scintigraphy, often leading to invasive procedures and psychological distress due to suspected malignancy. Hence, dermal tattoo pigments act as chronic triggers for distinct immunological host responses emphasizing the importance of thorough tattooing anamnesis when evaluating unexplained local or generalized lymphadenopathies including sarcoidosis.