Pseudoprogression of lung large cell neuroendocrine carcinoma resembling pancreatic cancer during durvalumab therapy.

A 74-year-old Asian man was referred for numb and painful sensation in the right upper limb. He was diagnosed with lung large cell neuroendocrine carcinoma and started receiving durvalumab therapy as second-line treatment. Sixteen days after the first dose, laboratory examination revealed increased liver enzyme levels and a marked inflammatory response.