Primary appendiceal mucinous adenocarcinoma in two first-degree relatives: case report and review

Carcinomas of the appendix are exceedingly rare tumors and have an annual age-adjusted incidence of around 0.4 cases per 100,000. Appendiceal adenocarcinoma accounts for < 0.5% of all gastrointestinal neoplasms and, of these, mucinous adenocarcinomas account for the majority. Published accounts of familial instances of primary appendiceal tumors are strikingly rare. We report two siblings who both developed primary mucinous adenocarcinomas. A genetics evaluation was conducted to determine if there was a recognizable underlying single gene disorder; no DNA mismatch repair defect was evident, and no other diagnosis was apparent. A review of appendiceal cancers seen at Mayo Clinic from l997 to the present was conducted to search for additional familial cases. Among 316 cases of primary appendiceal cancer of any histologic type, this sib pair was the only family reporting a second affected family member. The occurrence of appendiceal cancer in siblings may represent a random occurrence. An exceedingly rare predisposition syndrome cannot be ruled out

Primary Appendiceal Mucinous Adenocarcinoma

Primary Adenocarcinomas of the appendix are extremely rare tumor. We report a case of primary mucinous adenocarcinoma in a 40 year old lady misdiagnosed as having acute appendicitis. All the routine investigations were within normal limit. USG of abdomen showed dilated appendix with little fluid collection adjacent to it and no other abnormality was seen which suggested acute appendicitis. Appendicectomy was done and excised appendix was sent for histopathological examination. Mucinous Adenocarcinoma of the appendix was confirmed after histopathological examination. Right hemicolectomy was done as a second stage procedure. As some cases are incidentally discovered, this case emphasizes that histological examination of all appendicectomy specimens is mandatory