Reports that you run for a Case can be accessed from two places.
CaseStream
Click the icon in the Documents row on the CaseStream. Click the arrow button on the information block to display the report in your browser window. View or export to PDF or Excel.
Case Documents
Select Documents in the top menu. In the Document Gallery select the Case Documents tab. Scroll through the list to find the report you wish to view. (The documents are date ordered). Click to view and export to PDF or Excel.