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

Abstract

Primary adenocarcinoma of the appendix is a rare malignancy that constitutes < 0.5% of all gastrointestinal neoplasms. Moreover, primary signet ring cell carcinoma of the appendix is an exceedingly rare entity. We have encountered 15 cases of primary appendiceal cancer among 3389 patients who underwent appendectomy over the past 18 years. In the present report, we describe a rare case of primary signet ring cell carcinoma of the appendix with ovarian metastases and unresectable peritoneal dissemination occurring in a 67-year-old female patient. She underwent appendectomy and bilateral salpingo-oophorectomy with a laparoscopy procedure. She then received palliative systemic chemotherapy with 12 cycles of oxaliplatin, 5-flurorouracil, and leucovorin (FOLFOX-4). The patient currently is well without progression of disease 12 mo after beginning chemotherapy.

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.