2016f-080 basalcell biopsy cancer carcinoma casestudies diagnosis differential diseases endoscopicsurgery endoscopy eye-sockets facialneoplasms head headandneckneoplasms histopathology methods minimal-invasivechirurgie neck neoplasms neurochirurgie orbitalneoplasms pathology schädelbasiskrankheit skinneoplasms skullbase skullbaseneoplasms squamouscell surgery therapy tumor tumors vasculartissue