Case 57, poorly imaged area of adenocarcinoma. This image shows several image problems. The field was poorly focused and the nuclei appear smeared. Because the rest of the case had reasonably good imaging (including other levels of the same lesion), the pathologists could easily read around the artifact and arrived at the correct diagnosis.
Gilbertson et al. BMC Clinical Pathology 2006 6:4 doi:10.1186/1472-6890-6-4