Abstract / Summary
ABSTRACT Tumour‐infiltrating lymphocyte (TIL) therapy is a newly emerged effective treatment for advanced melanoma refractory to immune checkpoint inhibitors; however, its cutaneous adverse effects remain uncharacterized. We present the first case series describing dermatologic adverse effects associated with TIL therapy for malignant melanoma in five patients. These patients were treated with varying TIL regimens in combination with interleukin‐2 (IL‐2). The cutaneous reactions, which developed within 3−30 days following therapy, were primarily exanthems and ranged from self‐limited vascular proliferations to high‐risk morbilliform eruptions with systemic involvement. Patients were managed with supportive care and topical corticosteroids, with escalation to intravenous immunoglobulin in cases of severe systemic involvement. Four of the patients did not require dose adjustment or interruption of TIL therapy. One patient did require cessation of TIL therapy due to hypotension requiring vasopressors and acute kidney injury. The pathogenesis of these reactions is hypothesized to involve systemic immune activation and cytokine release following the infusion of activated T cells, with a potential contributory role of concurrent IL‐2 administration. As TIL therapy gains broader clinical use, recognition of its cutaneous adverse effects is increasingly important. This case series provides novel clinical and histopathological insights into TIL‐associated cutaneous eruptions and underscores the need for early dermatologic evaluation and monitoring to optimize patient outcomes.