Technique / Histology

Optical imaging technologies, such as reflectance and fluorescence spectroscopy, have shown the potential to provide enhanced detection of changes in the uterine cervix at clinical examination. This review focuses on fluorescence confocal endomicroscopy that enables in vivo microscopic imaging of the cervical epithelium in histological detail in real time. The microscopic imaging technique may permit 'see-and-treat' workflows in colposcopy through high-resolution fluorescence imaging of cellular and subcellular detail from the surface and subepithelial layers of the cervical mucosa. The device may be used in conjunction with a conventional colposcope. Preliminary data from clinical studies suggest that the device can be used to visualize features of the cervical epithelium including the squamo-columnar junction, dermal papillae and endocervical glands. Moreover, the technique has the ability to detect and grade precancerous changes of the cervical epithelium in conditions, such as cervical intraepithelial neoplasia, where prediction using colposcopy may be problematic. The early detection and diagnosis of gynecological abnormalities through the collection of 'optical' biopsies or targeted mucosal excisional biopsies have the potential to improve patient management through early therapeutic intervention and 'see-and-treat' strategies.

Identification of so-called "vulnerable plaque" or "high-risk" plaques have spawned manifold attempts to develop diagnostic tools capable to afford this task. This task is particularly challenging but the reward is high: local intervention on identified "vulnerable plaque" could preclude plaque thrombosis and possibly prevent acute coronary syndromes. Various imaging techniques are currently under investigation by extensive clinical testing to identify which could become the most sensible and specific modality for vulnerable plaque detection. Noninvasive techniques are fascinating for their easily applicability to a broad population but nowadays are not sufficiently powered for this task. The emerging technologies with the greatest resolution are indeed catheter-based and many intravascular modalities have been developed for identification of "vulnerable plaque". Among these, IVUS-Virtual Histology (IVUS-VH) is the most promising technique in the field. IVUS-VH offers an in vivo opportunity to assess plaque morphology and histology. IVUS-VH uses underlying frequency information along with echoes intensity, while grey-scale IVUS data are obtained from echoes of different intensity or amplitude. The major advantage of IVUS-VH is that it is based on a device that is practical for use in the clinical setting and that it generates a real-time assessment of plaque morphology. Unfortunately, numerous challenging issues still need to be overcome until the numerous "vulnerable plaques" could be identified and successfully treated. Future efforts may identify plaques that are on a trajectory of evolution toward a vulnerable state, and help us target interventions to those plaques most likely to develop plaque disruption and related complications.

Complete three-dimensional histology of excised skin tumour margins has a long tradition and, unfortunately, a multitude of names as well. Mohs, who introduced it, called it 'microscopically controlled surgery'. Others have described it as 'micrographic surgery', 'Mohs' micrographic surgery', or simply 'Mohs' surgery'. Semantic confusion became truly rampant when variant forms, each useful in its own way for detecting subclinical outgrowths of malignant skin tumours, were later introduced under such names as histographic surgery, systematic histologic control of the tumour bed, histological control of excised tissue margins, the square procedure, the perimeter technique, etc. All of these methods are basically identical in concept. All involve complete, three-dimensional histological visualization and evaluation of excision margins. Their common goal is to detect unseen tumour outgrowths. For greater clarity, the authors of this paper recommend general adoption of '3D histology' as a collective designation for all the above methods. As an added advantage, 3D histology can also be used in other medical disciplines to confirm true R0 resection of, for example, breast cancer or intestinal cancer.