PURPOSE: Histopathological examination for peripheral pulmonary lesions has been mainly based upon the light microscopic examination of thin-slice specimens with hematoxylin and eosin (H&E) staining. However, it takes at least a couple of days to create a slide glass for microscopic study. In order to obtain immediate microscopic images for peripheral pulmonary lesions, we used "Ultra high" magnification Endoscopy(Endocytoscopy). Endocytoscopy has 400-fold magnifying power. We assessed the usefulness of virtual histology by Endocytoscopy for peripheral pulmonary lesions.
METHODS: Thirty peripheral pulmonary lesions (adenocarcinoma: 17 lesions, squamous cell carcinoma: 4 lesions, small cell carcinoma: 2 lesions, metastatic tumor: 3 lesions, Giant cell carcinoma: 1 lesion, Baltoma 1 lesion, sclerosing pneumocytoma: 1 lesion, intra-pulmonary lymph node: 1 lesion).Methylene Blue (0.25, 0.5%) was dropped on the cut surface of the resected fresh peripheral pulmonary lesion after operation. The tip of the Endocytoscope was attached to the dyed surface of the resected peripheral pulmonary lesion and "Ultra high" magnified images were recorded. "Ultra high" magnified images were compared with histopathological findings with H&E staining. Pathologist tried to diagnose images of the Endocytoscopy without histopathological findings, and the diagnostic accuracy was evaluated.
RESULTS: Endocytoscopy showed structures of alveolus, interstitial tissue, cells (tumor cell, lymphocyte, etc.), and patterns of tumor. In particular, the findings of Endocytoscopy for bronchioloalveolar carcinoma and squamous cell carcinoma were strikingly similar the histopathological findings. Diagnostic accuracy of Endocytoscopy by a pathologist was 67%.
CONCLUSION: Virtual histology by Endocytoscopy were feasible for peripheral pulmonary lesions with characteristic structural patterns. This novel method enables us to obtain an immediate serial virtual microscopic section through a fresh specimen.
CLINICAL IMPLICATIONS: These early results encourage us to develop imaging relevant to conventional histopathology alongside the development of Endocytoscopy technology in the near future.
DISCLOSURE: Noriaki Kurimoto, No Financial Disclosure Information; No Product/Research Disclosure Information