The in vivo imaging by microSPECT/CT confirm that the anti-CEA pIgA is a suitable tool for the detection of mucosal tumours, particularly in lungs, but in vivo imaging is less sensitive (1 mm resolution) and uptake was detectable only for a intermediate tissue colonisation (0.08% ± 0.01%). This evidence concerns the gene CEACAM5 and neoplasm.