上段の造影CTで，図５の１〜図１０の７は虫垂と思われるが，図９で最大径3.5cmもあり通常の虫垂炎ではない．さらに図３から図９の↑は図９で虫垂と連続するが，内腔がつながっているかは不明の奇妙な構造物である．図４でガスと液状内容物を含み壁肥厚した腸管のようにも見える．手術で盲腸から発生する10×4cm大の腫瘤を認め（図Aと図B），他に虫垂らしきものを認めず，形成異常の虫垂と思われた（重複虫垂？： duplication of appendix？ ）．病理：虫垂は薄い壁の嚢胞となり線維化が著しい．並んで走行する部分は1.5cmに壁肥厚し嚢胞状で虫垂に類似する．

文献考察:重複虫垂（duplication of appendix）
Surg Clin North Am. 2000 Feb;80(1):295-318.
Appendix and cecum. Embryology, anatomy, and surgical applications.
Schumpelick V, Dreuw B, Ophoff K, Prescher A.
Surgeons should be familiar with surgery of the cecum and appendix because the diseases of this region, especially appendicitis, are the most common indications for surgical exploration. Usually, diagnosis of appendicitis and appendectomy are not difficult, but atypical location of the appendix or other anatomic anomalies can make the diagnosis of appendicitis and appendectomy difficult. In cases of atypical anatomy or diffuse clinical picture, especially in young adults or elderly patients, the spectrum of embryologic and anatomic anomalies must be kept in mind to make the correct treatment decision for individual patients. If doubt persists, explorative laparotomy must be performed to avoid overlooking rare, acute, intra-abdominal abnormalities.PMID: 10685154
追記：虫垂重複症は次のように分類される．１）Type A: Distal duplication with a common base(i.e.,bifid appendix:), Type B1: Two appendices originate from a common cecum on both sides of the ileocecal valve. Type B2: A normal appendix with a normal origin combined with a rudimentary form originating from one of the cecal teniae. Type B3: One normal-shaped and normal-positioned appendix is combined with another one originating from the right colon flexure. Type C: Double ceca, each with its own appendix.