Diagnosis of Basal Cell Carcinoma with Ex-vivo Confocal Laser Scanning Microscopy in a Real-life Setting

Ex-vivo confocal laser scanning microscopy provides a rapid alternative to routine histological processing using haematoxylin and eosin-stained sections. Previous studies suggest high diagnostic accuracy in basal cell carcinoma. This study investigates the diagnostic accuracy of confocal laser scanning microscopy reporting of basal cell carcinoma in a real-life setting and compares reporting by dermatopathologists inexperienced in use of confocal laser scanning microscopy with reporting by an expert in confocal laser scanning microscopy. A total of 334 confocal laser scanning microscopy scans were diagnosed by 2 dermatopathologists inexperienced in the diagnosis of confocal laser scanning microscopy as well as an experienced examiner of confocal laser scanning microscopy scans. The inexperienced examiners achieved a sensitivity of 59.5/71.1% and specificity of 94.8/89.8%. The experienced examiner achieved a sensitivity of 78.5% and specificity of 84.8%. Detection of tumour remnants in margin controls showed insufficient values among inexperienced (30.1/33.3%) and experienced (41.7%) investigators. The results of this study, of real-life setting basal cell carcinoma reporting with confocal laser scanning microscopy, found a lower diagnostic accuracy than published data regarding artificial settings. A poor accuracy in tumour margin control is clinically relevant and could restrict the use of confocal laser scanning microscopy in clinical routine. Prior knowledge of haematoxylin and eosin trained pathologists can be partially transferred to the reporting of confocal laser scanning microscopy scans; however, specific training is recommended.