Periappendiceal Infiltration Research Articles

Right hydronephrosis as a sign of complicated appendicitis

ObjectiveAcute appendicitis is known for one of the most common cause of acute abdomen. However, it is still challenging to clearly distinguish complicated from uncomplicated appendicitis preoperatively. We investigated the association between right hydronephrosis and complicated appendicitis compared with other computed tomography (CT) findings of acute appendicitis. Materials and methods1275 patients who pathologically diagnosed with acute appendicitis were included. They were classified into the complicated appendicitis and uncomplicated appendicitis groups based on their histopathological results. We reviewed their CT findings, including right hydronephrosis, appendiceal wall defect, periappendiceal abscess, extraluminal or intraluminal free air, appendicolith, appendiceal dilatation, appendiceal wall thickening, periappendiceal infiltration, periappendiceal fluid collection, and ascites. Comparison between the two groups was performed and the diagnostic performance of each CT finding was evaluated. The location of appendix and periureteral extension of periappendiceal infiltration were evaluated in patients with right hydronephrosis. ResultsOut of 1275 patients, 29 (2.3 %) patients showed right hydronephrosis. Right hydronephrosis was significantly related to complicated appendicitis with the odds ratio of 4.90 (95 % confidence interval, 1.62−14.83; P = 0.005). Right hydronephrosis yielded specificity of 99.3 %. All patients with right hydronephrosis accompanied with periappendiceal infiltration and 28 (96.6 %) patients showed periureteral extension. Subcecal and pelvic areas are the most common locations, with 11 (37.9 %) patients each. ConclusionThe presence of right hydronephrosis was specific finding for complicated appendicitis and it could be considered as one of indirect sign of complicated appendicitis.

How to Evaluate Appendices with Borderline Diameters on CT: Proposal of a Quick Solution to Overcome the Limitations of the Established CT Criteria

To propose a useful computed tomography (CT) criterion, the diameter with compression (DWC), especially in appendices with borderline diameters. We retrospectively collected 216 patients with visible appendices on CT after clinicopathologic confirmation of appendicitis. Each CT criterion of appendicitis was evaluated by an experienced abdominal radiologist: maximal outer diameter (MOD), DWC, mural thickness and enhancement, periappendiceal infiltration, and appendicolith. DWC is the expected diameter after deduction of the intraluminal compressible contents such as air and feces. All the CT criteria were compared in the appendicitis and nonappendicitis group. The areas under the receiver operating characteristic curve (AUC) of the MOD and the DWC were 0.967 and 0.973, respectively. The optimal cutoff value was 8.2mm for the MOD and 6.6mm for the DWC. Twenty-five of the 80 appendicitis patients (31.2%) and 62 of the 136 nonappendicitis patients (45.6%) had MODs between 5.7mm and 9.8mm in the overlap between the two groups. In this overlap, the AUC of the MODs declined sharply to 0.767, whereas the AUC of the DWCs remained 0.923. Use of the criterion of DWC >6.6mm yielded a sensitivity of 84.0%, a specificity of 88.7%, and an accuracy of 87.4%. There were no other criteria with both sensitivity and specificity >80% in the range of overlap. The proposed CT criterion of the DWC is not affected by normal distension or periappendiceal inflammation but only by true appendicitis. Therefore, DWC can improve the diagnostic performance of appendicitis regardless of the MOD.

Goblet cell carcinoid neoplasm of the appendix: Clinical and CT features

PurposeTo describe the clinical and CT imaging features of goblet cell carcinoid (GCC) neoplasm of the appendix. Methods and materialsA computer search of pathology and radiology records over a 19-year period at our two institutions was performed using the search string “goblet”. In the patients with appendiceal GCC neoplasms who had abdominopelvic CT, imaging findings were categorized, blinded to gross and surgical description, as: “Appendicitis”, “Prominent appendix without peri-appendiceal infiltration”, “Mass” or “Normal appendix”. The CT appearance was correlated with an accepted pathological classification of: low grade GCC, signet ring cell adenocarcinoma ex, and poorly differentiated adenocarcinoma ex GCC group. ResultsTwenty-seven patients (age range, 28–80years; mean age, 52years; 15 female, 12 male) with pathology-proven appendiceal GCC neoplasm had CT scans that were reviewed. Patients presented with acute appendicitis (n=12), abdominal pain not typical for appendicitis (n=14) and incidental finding (n=1). CT imaging showed 9 Appendicitis, 9 Prominent appendices without peri-appendiceal infiltration, 7 Masses and 2 Normal appendices. Appendicitis (8/9) usually correlated with typical low grade GCC on pathology. In contrast, the majority of Masses and Prominent Appendices without peri-appendiceal infiltration were pathologically confirmed to be signet ring cell adenocarcinoma ex GCC. Poorly differentiated adenocarcinoma ex GCC was seen in only a small minority of patients. Hyperattenuation of the appendiceal neoplasm was seen in a majority of cases. ConclusionsGCC neoplasm of the appendix should be considered in the differential diagnosis in patients with primary appendiceal malignancy. Our cases demonstrated close correlation between our predefined CT pattern and the pathological classification.

Actinomycosis of the appendix mimicking appendiceal tumor: A case report

Actinomycosis is an uncommon chronic infectious disease. Common sites of involvement include the cervicofacial, thoracic and abdominopelvic regions. In abdominopelvic actinomycosis, the ileocecal region, including the appendix, is the most commonly involved site. In some reports, limited appendiceal actinomycosis has revealed a thickened appendiceal wall with peri-appendiceal inflammation as acute appendicitis or perforated appendicitis. We experienced pathologically confirmed intraluminal limited appendiceal actinomycosis without peri-appendiceal infiltration. Here, we report the computed tomography and ultrasound findings.