Pseudoprogression of Melanoma Brain Metastases

Purpose of Review: Immune checkpoint inhibitors are increasingly being used to treat melanoma brain metastases. One potential complication of immune checkpoint inhibitors is a phenomenon called pseudoprogression, in which a tumor transiently increases in size due to lymphocyte infiltration. This article reviews the characteristics of pseudoprogression and their clinical implications. Recent Findings: Pseudoprogression can be challenging to differentiate from true progression noted clinically or radiographically, thereby complicating management decisions and potentially confusing patients and their families. The transient tumor enlargement can also cause symptoms that mimic true tumor progression. Summary: Because the use of immunotherapy on melanoma brain metastases is a relatively new treatment paradigm, there is limited evidence to guide clinical decision-making and prognostication related to pseudoprogression.