Fibroblasts are important players in proliferation, invasion, migration and metastasis of cancer cells. Until now, histological methods such as hematoxylin and eosin (H and E) staining are still a gold standard to assess fibroblasts in traditional histopathology. Multiphoton microscopy (MPM) has become a key technology for biological tissues imaging without staining at the cellular level. In this study, MPM based on two-photon excited fluorescence (TPEF) and second harmonic generation (SHG) was used to identify the fibroblasts in breast cancer tissue. Normal fibroblasts with spindle shape and abnormal fibroblasts with stellate shape could be clearly obtained by MPM.
Florid type is a kind of morphological variation of lobular carcinoma in situ (LCIS). Florid lobular carcinoma in situ (FLCIS) has the same cytological features as LCIS, often associated with comedo-type necrosis. Unlike classic lobular carcinoma in situ (CLCIS), which is often managed with close observation or chemoprevention, the treatment guidelines recommend that FLCIS be managed in the same way as ductal carcinoma in situ (DCIS). Therefore, it is critical to accurately identify FLCIS for management purposes. Recently, multiphoton microscopy (MPM) has become a powerful imaging tool for label-free detection of biological tissue. In this work, we obtain high-resolution images of unstained normal and diseased breast specimens by MPM. In order to verify the imaging details, we also obtained hematoxylin-eosin (H and E) stained images of corresponding tissues to compare with the MPM images. Our results indicate that MPM can identify FLCIS and CLCIS through histological characteristics, including cell morphology and collagen structure. With the further improvement of MPM, its diagnostic capabilities of real-time and non-invasive may provide a new option for early detection of breast tumor
Macrophages are at the center of the invasion and play a protumoral role in the tumor microenvironment. They can facilitate angiogenesis, extracellular matrix remodeling, invasion and migration of cancer cells, while inhibit the antitumoral immune surveillance. Tumor-associated macrophages are a major component of malignant tumors, which can stimulate the progress of tumors. In many human cancers, the presence of macrophages in tumor microenvironment has been correlated with unfavorable prognosis. Therefore, visual diagnosis of macrophages in tumor microenvironment is great significance for us to comprehend the occurrence and progress of tumor. Multiphoton microscopy (MPM) with subcellular resolution based on second harmonic generation (SHG) and two-photon excited fluorescence (TPEF) is very suitable for real-time detecting morphological and structural changes in biological tissues without tissue staining and exogenous probe molecule. In this study, we describe the use of label-free MPM for analyzing the intratumoral distribution and morphological changes of macrophages in breast tumor microenvironment. Our results indicated that MPM can accurately identify macrophages in breast tumor tissues. MPM images were well consistent hematoxylin and eosin (H&E) stained images. This work would provide the basis for further quantifying these changes using MPM. With the development of miniaturized imaging devices, MPM may be a promising imaging technique for clinicians to study various structural features in tumor microenvironment.