The systems described herein include tools for computer-assisted evaluation of objective characteristics of pathologies. A diagnostic system arranged according to the teachings herein provides computer support for those tasks well suited to objective analysis, along with human decision making where substantial discretion is involved. Collaborative diagnosis may be provided through shared access to data and shared control over a diagnostic tool, such as a telemicroscope, and messaging service for clinicians who may be at remote locations. These aspects of the system, when working in cooperation with one another, may achieve improved diagnostic accuracy or early detection for pathologies such as lymphoma.