右下腹部痛(Right Lower Quadrant Pain)シリーズ18 EXPERT COURSE 解答 【症例 RE 87】

急性虫垂炎.Acute appendicitis.






脂肪組織が少ないので診断困難な症例であるが,右側結腸(A:上行結腸,C:盲腸)は図11で盲端になる.図3と図4のTI が回腸末端であるが,その先は頭側へ上行するようだ.図10の1が虫垂根部で,図8の3から拡張し始め,図3の8で盲端になる.最大径1cm程度に腫大し,壁は造影され,図2〜図4で虫垂先端周囲の脂肪組織の濃度上昇を認め(▲),急性虫垂炎と診断できる.手術および病理所見:phlegmonous appendicitis.






文献考察:CTで虫垂を認識できないで,周囲炎症所見もない時の急性虫垂炎の可能性は2%
AJR Am J Roentgenol. 2004 Oct;183(4):889-92.
The nonvisualized appendix: incidence of acute appendicitis when secondary inflammatory changes are absent.
Nikolaidis P, Hwang CM, Miller FH, Papanicolaou N.
OBJECTIVE: The objective of our study was to assess the importance of nonvisualization of the appendix and its association with acute appendicitis on helical CT when secondary inflammatory changes are absent. MATERIALS AND METHODS: After we received institutional review board approval, CT scans of 366 consecutive patients obtained for lower abdominal or right lower quadrant pain and to rule out appendicitis were retrospectively reviewed. Images were reviewed by an experienced abdominal radiologist and compared with the formal interpretation. The amount of right lower quadrant and pericecal fat was quantified on a scale of 0 (none) to 2 (abundant). Patients with a nonvisualized appendix and other findings compatible with acute appendicitis-such as abscess formation, localized perforation, periappendiceal fat stranding, or appendicolith-were excluded. RESULTS: The appendix could not be visualized by both reviewers in 46 (13%) of 366 cases. CT findings indicated another cause for the patient's symptoms in 12 cases (26%), including gastrointestinal and genitourinary processes. An alternate diagnosis was subsequently reached in 11 additional patients (24%) with follow-up imaging or clinical evaluation. Only one patient (2%) with a nonvisualized appendix had acute appendicitis, proven by surgical pathology. In this patient, there was paucity of fat in the right lower quadrant. CONCLUSION: In the absence of a distinctly visualized appendix and secondary inflammatory changes, the incidence of acute appendicitis is low. Nonvisualization of the appendix even when a small amount of fat is present in the right lower quadrant may safely exclude acute appendicitis if no secondary CT findings are present.PMID: 15385277
  【参照症例】   1. 右下腹部痛シリーズ4 【症例 RE 19】
2. 右下腹部痛シリーズ8 【症例 RE 38】

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