Late and isolated pseudoprogressions of non-small cell lung cancer under anti-PD-1 in the adrenal glands: about two cases

Pseudoprogression (PsP) rarely occurs late after the initiation of immunotherapy and exceptionally in the adrenal glands. We report two unique cases of late isolated PsP in the adrenal glands of metastatic non-small cell lung cancer (mNSCLC), occurring 10 months after the initiation of nivolumab monotherapy. This provides proof of concept that late PsP can occur in the adrenal glands of mNSCLC patients treated with anti-PD-1. Clinicians should be aware of this potential diagnosis as an alternative to true tumor progression under immunotherapy, with important implications for the subsequent management. The neuro-immune interface may play a role in the development of PsP in the adrenal glands.