Pseudoprogression of pleural effusion in lung cancer treated with immunotherapy: a case report.

ABSTRACT:

Background

Pseudoprogression (PsP) is an atypical response phenomenon increasingly recognized in patients treated with immune checkpoint inhibitors (ICIs), characterized by transient radiologic worsening before subsequent tumor regression. This response pattern complicates the interpretation of treatment efficacy and poses a challenge in distinguishing true disease progression from a treatment-related immune effect. While PsP is most commonly observed as an initial increase in tumor size or the appearance of new lesions, its presentation as pleural effusion is exceedingly rare and may be misdiagnosed as disease progression or immune-related adverse events (irAEs). Prompt recognition of this phenomenon is essential to avoid premature discontinuation of potentially effective therapy.

SUBMITTER: Kaneda H 

PROVIDER: S-EPMC12541859 | biostudies-literature | 2025 Sep

REPOSITORIES: biostudies-literature