Appendiceal Adenocarcinoma Presenting as an Iatrogenic Appendicitis

Abstract

Introduction: Appendiceal carcinoma is a rare entity. Of all types of cancer of appendix, adenocarcinoma of appendix is 0.08% of all cancers, accounting for 0.5% of all gastrointestinal cancers. We report a case of appendiceal adenocarcinoma diagnosed following polypectomy complicated with an iatrogenic cecal perforation and appendicitis. Case: 64-year-old man was referred for screening colonoscopy. He denied abdominal pain, diarrhea or constipation, melena/hematochezia and change in size or caliber of stool. He denied family history of colon cancer or polyps. Colonoscopy revealed 1.5-2.0 cm sessile cecal polyp surrounding appendicular orifice which was biopsy proven tubulovillous adenoma. A surgical consultation was done for cecectomy but patient declined surgery. A repeat colonoscopy and piecemeal cecal polypectomy was done. Following day of his colonoscopy, patient presented to emergency department (ED) with complaints of right lower quadrant abdominal pain, fever and chills. Patient denied nausea, vomiting, hematochezia or melena. His vital signs were stable but he had right lower quadrant tenderness and guarding. Laboratory evaluation revealed WBC 22,000 with left shift, and lactic acid level of 0.8. Computed tomography of abdomen/pelvis showed dilated appendix at 2.2 cm with surrounding inflammatory changes suggestive of appendicitis. Patient was taken for emergent laparoscopic appendectomy which was converted to open appendectomy secondary to cecal perforation. Pathologic examination of specimen of appendix revealed grade 2 adenocarcinoma of appendix arising in villous adenoma. Patient underwent second stage procedure involving right hemicolectomy and currently on chemotherapy treatment. Discussion: Cancer of appendix is found incidentally in 1% of all appendectomies. Primary appendiceal adenocarcinoma accounts for 10% of malignant tumors of appendix. Appendiceal adenocarcinoma is rarely diagnosed preoperatively. Most often patients present with appendicitis, but sometimes completely asymptomatic. Imaging with CT scan can help reveal mucocele or calcification in appendix or sometimes diffuse peritoneal locules. Right hemicolectomy is the treatment of choice along with 5 FU based chemotherapy for nodal positive tumors. Prognosis is based on type of the tumor and also on the size and grade of tumor.Figure: Colonoscopy images showing cecal polyp surrounding appendiceal orifice.