By electron microscopy (EM), features of a carcinoma can be seen. This adenocarcinoma demonstrates several features typical of a neoplasm of epithelial origin, including the junctional complex (tight junction at the asterisk and the desmosomes at crosses). The mucin granule (M) and lumenal microvilli at the upper right are also typical for an adenocarcinoma. EM is occasionally employed as a diagnostic tool for neoplasms.