Intramucosal Adenocarcinoma of the Appendix

We read with interest the recent article by Sakamoto et al. [1] on the finding of a small elevated lesion inside the orifice of the appendix. The lesion was removed by polypectomy, and histopathology showed that it was a well-differentiated adenocarcinoma. The patient subsequently underwent laparoscopy-assisted ileocecal resection with lymph-node dissection. We would like to present here a report of a case in which there were similar findings.

A 68-year-old woman was admitted suffering from transient loss of vision. The ophthalmological examination was normal, and the physical examination showed normal findings with the exception of lymph nodes with a diameter of 2 cm in the left axillary and supraclavicular region. No abdominal masses or tenderness were found. The laboratory parameters were normal, except for anemia with a hemoglobin level of 8.8 g/dl (normal range 13.4-17.5 g/dl). The left axillary lymph node was surgically removed, and histopathology revealed a poorly differentiated signet-ring cell adenocarcinoma.

Diagnostic procedures were carried out to detect the primary tumor. Upper gastrointestinal endoscopy revealed no pathological changes, with the exception of an axial hiatal hernia 3 cm in diameter. However, slightly diminished expansion of the stomach was noted on inflation. Biopsies were not taken at this stage, since the gastric mucosa appeared normal. During a subsequent colonoscopic examination, two small polypoid lesions were found in the region of the vermiform appendix. The first small nodular polypoid lesion, with a diameter of 4 mm, was located about 1 cm from the appendix. A biopsy was taken, and histology revealed hyperplastic colonic mucosa. The second small nodular polypoid lesion was located in the orifice of the appendix (Fig. [1]). The mucosal surface had a normal appearance. Several biopsies were taken from the surface and depth of the lesion, and histology revealed a poorly differentiated adenocarcinoma. Histology and additional immunohistochemical analyses demonstrated that the previous axillary histology sample and the tumor in the appendiceal orifice were derived from a metastatic signet-ring cell adenocarcinoma. Subsequently, upper gastrointestinal endoscopy was repeated, and multiple biopsies were taken from the gastric antrum, body, and fundus. Histopathology revealed a poorly differentiated signet-ring cell adenocarcinoma in the majority of samples taken from the gastric body. Immunohistochemical staining of the tumor infiltrates showed that they were strongly positive for pan-cytokeratin (AE1/3) and cytokeratin 7, as well as estrogen receptor and human milk fat globulin-2 (HMFG-2), whereas progesterone receptor, thyroid transcription factor-1 (TTF-1), and surfactant were negative. On the basis of histology and immunohistochemical staining, these lesions appeared to be metastases of a breast cancer. However, at this stage, the patient refused additional diagnostic procedures and is currently in a stable condition while considering additional diagnostic measures and systemic chemotherapy.

Figure 1 A small nodular polypoid lesion in the orifice of the appendix, histologically shown to represent a metastatic signet-ring cell adenocarcinoma.

This case report highlights the fact that a polyp in the appendiceal orifice may not only represent a primary adenocarcinoma, but may also be a manifestation of metastatic disease. These patients must therefore be carefully examined for signs or manifestations of disseminated metastatic disease, and in these circumstances routine biopsies should be considered. As mentioned by Sakamoto et al., a careful search should be carried out not only for synchronous neoplasms but also for a primary tumor.

Reference

• 1 Sakamoto I, Watanabe S, Sakuma T. et al . Intramucosal adenocarcinoma of the appendix: how to find and how to treat.  Endoscopy. 2003;  35 785-787