MR‐Guided Laser Interstitial Thermal Therapy for Recurrent Glioblastoma: A Case Report With Novel Insights Into Histopathological Changes and Immunological Responses

Summary MR‐guided laser interstitial thermal therapy (LITT) induces distinct zonal histopathological changes in recurrent glioblastoma, including central coagulation necrosis surrounded by a reactive immune cell rim of CD68 + , CD163 + and PD‐L1 + macrophages. Increased CD8 + cytotoxic T‐cell infiltration was observed in the perilesional zone (23.5 cells/mm 2 ) relative to outer dense tumour tissue (19.6 cells/mm 2 ), suggesting that LITT may promote a more immunostimulatory local microenvironment. The perilesional transition zone adjacent to the ablation site showed reduced tumour cellularity and lower proliferative activity (Ki‐67) compared to the outer dense tumour tissue, indicating a gradient of thermal effect on tumour biology. These findings provide the first systematic histopathological and immunohistochemical characterisation of human recurrent glioblastoma tissue following LITT, establishing a framework for future studies combining LITT with immunotherapy.