BACKGROUND: Vivascope 2500 ex vivo confocal microscopy (EVCM) is an emerging optical imaging device that allows nuclear level resolution of freshly excised tissues. EVCM provides, rapid real-time pathological examination in many subspecialties of pathology including skin, prostate, breast, liver, etc. In contrast to traditional time-consuming frozen sectioning and histological analysis.
OBJECTIVE: To evaluate the current state of EVCM utilization.
METHODS: This study highlights the advantages, limitations, and prospects of EVCM in skin pathology.
RESULTS: Our findings demonstrate that EVCM is a promising adjunctive tool to assess margins in Mohs surgery and to provide rapid, accurate diagnosis of cutaneous tumors, infectious and inflammatory diseases.
CONCLUSIONS: EVCM is a revolutionary device that can be used as an adjunct to paraffin-fixed, hematoxylin and eosin-stained slides and frozen sectioning. Additional refinements are required before EVCM can be used as an alternative to frozen sectioning or traditional tissue processing.

BACKGROUND: A microscopic analysis of tissue is the gold standard for cancer detection. Hematoxylin-eosin (HE) for the reporting of prostate biopsy (PB) is conventionally based on fixation, processing, acquisition of glass slides, and analysis with an analog microscope by a local pathologist. Digitalization and real-time remote access to images could enhance the reporting process, and form the basis of artificial intelligence and machine learning. Fluorescence confocal microscopy (FCM), a novel optical technology, enables immediate digital image acquisition in an almost HE-like resolution without requiring conventional processing.
OBJECTIVE: The aim of this study is to assess the diagnostic ability of FCM for prostate cancer (PCa) identification and grading from PB.
METHODS: This is a prospective, comparative study evaluating FCM and HE for prostate tissue interpretation. PBs were performed (March to June 2019) at a single coordinating unit on consecutive patients with clinical and laboratory indications for assessment. FCM digital images (n = 427) were acquired immediately from PBs (from 54 patients) and stored; corresponding glass slides (n = 427) undergoing the conventional HE processing were digitalized and stored as well. A panel of four international pathologists with diverse background participated in the study and was asked to evaluate all images. The pathologists had no FCM expertise and were blinded to clinical data, HE interpretation, and each other\'s evaluation. All images, FCM and corresponding HE, were assessed for the presence or absence of cancer tissue and cancer grading, when appropriate. Reporting was gathered via a dedicated web platform.
UNASSIGNED: The primary endpoint is to evaluate the ability of FCM to identify cancer tissue in PB cores (per-slice analysis). FCM outcomes are interpreted by agreement level with HE (K value). Additionally, either FCM or HE outcomes are assessed with interobserver agreement for cancer detection (presence vs absence of cancer) and for the discrimination between International Society of Urologic Pathologists (ISUP) grade = 1 and ISUP grade > 1 (secondary endpoint).
CONCLUSIONS: Overall, 854 images were evaluated from each pathologist. PCa detection of FCM was almost perfectly aligned with HE final reports (95.1% of correct diagnosis with FCM, κ = 0.84). Inter-rater agreement between pathologists was almost perfect for both HE and FCM for PCa detection (0.98 for HE, κ = 0.95; 0.95 for FCM, κ = 0.86); for cancer grade attribution, only a moderate agreement was reached for both HE and FCM (HE, κ = 0.47; FCM, κ = 0.49).
CONCLUSIONS: FCM provides a microscopic, immediate, and seemingly reliable diagnosis for PCa. The real-time acquisition of digital images-without requiring conventional processing-offers opportunities for immediate sharing and reporting. FCM is a promising tool for improvements in cancer diagnostic pathways.
UNASSIGNED: Fluorescence confocal microscopy may provide an immediate, microscopic, and apparently reliable diagnosis of prostate cancer on prostate biopsy, overcoming the standard turnaround time of conventional processing and interpretation.

Ex vivo fluorescence confocal microscopy (FCM) is an optical technology that provides fast H&E-like images of freshly excised tissues, and it has been mainly used for \"real-time\" pathological examination of dermatological malignancies. It has also shown to be a promising tool for fast pathological examination of prostatic tissues. We aim to create an atlas for FCM images of prostatic and periprostatic tissues to facilitate the interpretation of these images. Furthermore, we aimed to evaluate the learning curve of images interpretation of this new technology. Eighty fresh and unprepared biopsies obtained from radical prostatectomy specimens were evaluated using the FCM VivaScope® 2500 M-G4 (Mavig GmbH, Munich, Germany; Caliber I.D.; Rochester NY, USA) by two pathologists. Images of FCM with the corresponding H&E are illustrated to create the atlas. Furthermore, the two pathologists were asked to re-evaluate the 80 specimens after 90 days interval in order to assess the learning curve of images\' interpretation of FCM. FCM was able to differentiate between different types of prostatic and periprostatic tissues including benign prostatic glands, benign prostatic hyperplasia, high-grade intraepithelial neoplasm, and prostatic adenocarcinoma. As regards the learning curve, FCM demonstrated a short learning curve. We created an atlas that can serve as the base for urologists and pathologists for learning and interpreting FCM images of prostatic and periprostatic tissues. Furthermore, FCM images is easily interpretable; however, further studies are required to explore the potential applications of this new technology in prostate cancer diagnosis and management.