Ringvormige afwijkingen op een longscan

A 25-year-old man was treated with pembrolizumab for a relapsed-refractory primary mediastinal large B-cell lymphoma. On an evaluation PET-CT scan multiple ‘reversed halo signs’ were noticed. No infectious cause was established and we diagnosed the lesions as pembrolizumab-induced pneumonitis, an immune-related adverse event.

Conflict of interest and financial support: none declared.