In vivo intraoperative confocal microscopy for real-time histopathological imaging of brain tumors

Frozen-section analysis is the current standard for the intraoperative diagnosis of brain tumors. Intraoperative confocal microscopy is an emerging technology with the potential to visualize tumor histopathological features and cell morphology in real time. The authors report their findings using this new intraoperative technology in vivo with sodium fluorescein contrast during the course of 50 microsurgical tumor resections.

Eighty-eight regions were visualized with confocal microscopy, and corresponding biopsy samples were examined with routine neuropathological analysis. The tumors studied included meningiomas, schwannomas, gliomas of various grades, and a hemangioblastoma. The confocal microscopic features of each tumor and of various artifacts inherent to the technology were documented. A pathologist working in a blinded fashion reviewed a subset of the images in a further evaluation of the usefulness of the device as a diagnostic tool.

Overall, intraoperative confocal imaging correlated surprisingly well with corresponding traditional histological findings, including the identification of many pathognomonic cytoarchitectural features of various brain tumors. In the blinded study, 26 (92.9%) of 28 lesions were diagnosed correctly.

Further study will be necessary for better definition of the role of intraoperative confocal microscopy as a routine adjunct for intraoperative brain tumor diagnosis.