Nivolumab-induced lichenoid granulomatous stomatitis in a patient with advanced melanoma: A case report

Lichenoid granulomatous reactions (LGR) are granulomatous inflammations of the skin and oral mucosa, also sharing features of lichenoid lesions. Thus, the present study refers to lichenoid granulomatous dermatitis (LGD) and lichenoid granulomatous stomatitis (LGS). LGR is a condition that can be triggered by drugs, diseases or environmental causes. In the present case study, anti-PD1 (nivolumab) medication had a detrimental effect on the oral mucosa, which clinicaly and histologicaly proved to be LGS. Checkpoint inhibitors consitute a cornerstone in the current treatment of several types of cancer, of which cutaneous melanoma is the best example. Oral lichenoid responses following anti-PD-1 therapy have been recorded in few case reports and small case series. To the best of our knowledhe, this is the first case of LGS being reported as a side effect of immune checkpoint inhibitor treatment.