Nonmelanoma skin cancer is the most common form of human cancer. Therefore, there is a strong need for high-resolution detection and microscopically controlled removal of these neoplasms. Currently pathologists use microscopes at low power to view tumor margins and at high power to inspect cell features for diagnosis and management of nonmelanoma skin cancers. We propose to develop a multimodal device that will enable both wide-field and high-resolution imaging in vivo and in real time. The device will combine the capabilities of the CCD macro-imaging that enables rapid inspection of a superficial tissue layer over large surfaces, and confocal microscopy that allows imaging within turbid media with resolution comparable to that of histology. The instrument will zoom between these modes, allowing the wider view to direct the high resolution view. Both modes will acquire images in reflectance, fluorescence, and fluorescence polarization. To enhance the contrast of the acquired images, we will use an FDA-approved conventional histological stain, non-toxic at low concentrations, i.e. Methylene Blue, to mimic the staining pattern of H&E histopathology. The feasibility of the technology will be explored by in vitro and in vivo pilot trials with excised human nonmelanoma skin cancer specimens and in small animals, respectively. During the technology development stage three pilot trials will be conducted. The first trial with excised nonmelanoma skin cancer specimens is designed for determining diagnostic features in optical images by comparison to histology. In the course of the second trial, the diagnostic criteria defined by the first stage will be used in a clinical trial, when the system will be employed for imaging open surgical fields during Mohs micrographic removal of nonmelanoma skin cancers in humans. Finally, the diagnostic capability of the developed technology will be tested in small animals by imaging lesions suspicious for squamous cell carcinoma and comparing the results to the diagnosis, based on the analysis of histopathology. The noninvasive device and methods developed in the course of this project will enable identification of tumor margins and small tumor nests in situ, leading to improved outcomes of cancer treatments. The diagnostic application of this technology holds the potential to replace biopsy, thus reducing morbidity and time associated with that invasive procedure.