Primary signet ring cell carcinoma of the appendix: A rare case report and our 18-year experience

Figure 1 Contrast enhanced CT axial scan (A) and coronal reformatted image (B) showing massive ascites in abdominal cavity. Appendix is prominently seen with mild thickening (arrowed). Coronal reformatted images (C and D) showing increased reticulonodular densities (arrows in C) along the omentum representing carcinomatosis peritonei with no definite evidence of mass like lesion in adnexa (arrows in D).

Figure 2 Histologic examination showing a signet ring cell carcinoma infiltrating vermiform appendix (A) and metastasizing to the ovary (B) (HE, × 400) with diffuse, strong immunoreactivity against cytokeratin 20 (C) and CDX-2 (D) in the tumor cells.