Figure 1.

(A–D) Histopathological variants of colorectal cancer. (A) Mucinous adenocarcinoma characterized by abundant extracellular mucin production; (B) signet ring-cell carcinoma with prominent intracytoplasmic mucin deposition, causing displacement and molding of tumor-cell nuclei; (C) medullary carcinoma characterized by sheets of malignant cells with vesicular nuclei with prominent nucleoli and abundant eosinophilic cytoplasm (note prominent lymphocytic infiltration of the tumor tissue); (D) micropapillary adenocarcinoma with characteristic small papillary and trabecular tumor-cell clusters within stromal spaces mimicking vascular channels.