ORIGINAL ARTICLE ANZJSurg.com
Dilemma of mucosal appendicitis: a clinico-pathological entity? A retrospective cohort study Ryo Mizumoto,*† Adam T. Cristaudo,*† Nai Kid Lai,*† Gamini Premaratne*† and Rasika Hendahewa*† *Department of Surgery, Caboolture Hospital, Caboolture, Queensland, Australia and †School of Medicine, The University of Queensland, St Lucia, Queensland, Australia
Key words Alvarado score, histopathology appendicitis, imaging and radiology of appendicitis, mucosal and submucosal appendicitis, negative appendicectomy. Correspondence Dr Ryo Mizumoto, Department of Surgery, Caboolture Hospital, McKean Street, Caboolture, QLD 4510, Australia. Email: [email protected] R. Mizumoto BSc, MBBS; A. T. Cristaudo MBBS, MS; N. K. Lai MBBS; G. Premaratne FRACS; R. Hendahewa MBBS, MS, MRCS, FRACS, FICS. This study was presented at the Royal Australasian College of Surgeons 85th Annual Scientific Congress, Brisbane Convention Centre, May 2016. Accepted for publication 14 September 2016. doi: 10.1111/ans.13820
Abstract Background: The presence of mucosal inflammation within appendicectomy specimens is poorly described in the literature, and there is debate regarding the clinical significance of this histological finding. The aim of this study is to correlate clinical and radiological data with histologically confirmed acute mucosal appendicitis (MA). Methods: A retrospective cohort study was performed to identify all patients who underwent appendicectomy over 5 years at Caboolture Hospital. Data were collected in regards to clinical Alvarado score, pathological specimen findings, radiological findings and coincidental conditions, and comparison made between MA and negative appendicectomy groups. Results: A total of 1347 appendicectomy specimens and data were reviewed. Of these, 219 (16%) specimens were microscopically confirmed to have acute mucosal inflammation, 150 (68%) were females. Median age was 19 14 years. A total of 243 (18%) were histologically negative. There was a statistically significant difference in mean Alvarado score in the MA group (5.0 1.9 versus 4.3 1.8, P = 0.0002). Patients with MA are more likely to report migratory pain (48.4 versus 31.4%, P = 0.0001) and rebound tenderness (24.9 versus 14.6%, P = 0.002). Computed tomography and ultrasound scans were negative in 74.1 and 72.6%, respectively, in patients with MA. More MA patients benefited from appendicectomy compared with the negative appendicectomy group (82 versus 63%, P = 10 (%)
Neutrophils (%)
Mean Alvarado score out of 10
31.4 48.4 0.000003
28.0 33.0 0.071
60.7 59.3 0.371
96.2 88.2 0.78
14.6 24.9 0.002
7.5 8.1 0.646
32.2 35.3 0.17
27.2 31.7 0.093
4.3 1.8 5.0 1.9 0.000183
N/V, nausea/vomiting; RIF, right iliac fossa; WCC, white cell count.
Table 3 CT and USS findings for histologically positive and negative appendicectomies
Mucosal appendicitis Negative histology Other appendicitis – transmural/gangrenous/ perforated CT, computed tomography; USS, ultrasound scan.
© 2016 Royal Australasian College of Surgeons
CT positive (%)
CT negative (%)
Total CT
USS positive (%)
USS negative (%)
Total USS
7 (25.9) 9 (25.7) 234 (96.7)
20 (74.1) 26 (74.3) 8 (3.3)
27 35 242
37 (27.4) 35 (22.4) 195 (64.8)
98 (72.6) 121 (77.6) 106 (35.2)
135 156 301
4
All patients confirmed to have MA and negative appendicectomies were retrospectively chart reviewed to calculate the Alvarado score. Patients with MA had a statistically significant higher scores (5.0 1.9) compared with patients who had negative appendicectomies (4.3 1.8). This is taking into account that patients with negative appendicectomies had higher incidence of other concurrent pathology (Table S3), and this also reflects the utility of Alvarado score in that it has a higher negative predictive value at lower scores.17 Patients with MA are more likely to report migratory pain (48.4 versus 31.4%, P = 0.000003) and rebound tenderness (24.9 versus 14.6%, P = 0.002). The differences between anorexia, nausea/vomiting, right iliac fossa tenderness, temperature and laboratory findings were not statistically significant. Patients were clinically reviewed post-operatively in the outpatients department. More patients in the MA group were well on follow-up compared with the negative appendicectomy group (82 versus 67%, P = 0.0002). There have been no previous studies examining the utility of CT and USS for MA. The results in this study show that CT and USS generally have a lower detection rate for MA, however, CT has high sensitivity and specificity in cases of transmural appendicitis. A total of 74.1 and 72.6% of MA is undetectable on CT and USS, respectively, therefore a high index of clinical suspicion should lead the clinician to suspect a diagnosis of MA in young female patients with low Alvarado scores, in the absence of other obvious clinical pathologies. On review of coincidental conditions, there was a statistically significant higher proportion of other co-existing pathology in the negative appendicectomy group compared with the MA group (37 versus 18%, P =
Dilemma of mucosal appendicitis: a clinico-pathological entity? A retrospective cohort study Ryo Mizumoto,*† Adam T. Cristaudo,*† Nai Kid Lai,*† Gamini Premaratne*† and Rasika Hendahewa*† *Department of Surgery, Caboolture Hospital, Caboolture, Queensland, Australia and †School of Medicine, The University of Queensland, St Lucia, Queensland, Australia
Key words Alvarado score, histopathology appendicitis, imaging and radiology of appendicitis, mucosal and submucosal appendicitis, negative appendicectomy. Correspondence Dr Ryo Mizumoto, Department of Surgery, Caboolture Hospital, McKean Street, Caboolture, QLD 4510, Australia. Email: [email protected] R. Mizumoto BSc, MBBS; A. T. Cristaudo MBBS, MS; N. K. Lai MBBS; G. Premaratne FRACS; R. Hendahewa MBBS, MS, MRCS, FRACS, FICS. This study was presented at the Royal Australasian College of Surgeons 85th Annual Scientific Congress, Brisbane Convention Centre, May 2016. Accepted for publication 14 September 2016. doi: 10.1111/ans.13820
Abstract Background: The presence of mucosal inflammation within appendicectomy specimens is poorly described in the literature, and there is debate regarding the clinical significance of this histological finding. The aim of this study is to correlate clinical and radiological data with histologically confirmed acute mucosal appendicitis (MA). Methods: A retrospective cohort study was performed to identify all patients who underwent appendicectomy over 5 years at Caboolture Hospital. Data were collected in regards to clinical Alvarado score, pathological specimen findings, radiological findings and coincidental conditions, and comparison made between MA and negative appendicectomy groups. Results: A total of 1347 appendicectomy specimens and data were reviewed. Of these, 219 (16%) specimens were microscopically confirmed to have acute mucosal inflammation, 150 (68%) were females. Median age was 19 14 years. A total of 243 (18%) were histologically negative. There was a statistically significant difference in mean Alvarado score in the MA group (5.0 1.9 versus 4.3 1.8, P = 0.0002). Patients with MA are more likely to report migratory pain (48.4 versus 31.4%, P = 0.0001) and rebound tenderness (24.9 versus 14.6%, P = 0.002). Computed tomography and ultrasound scans were negative in 74.1 and 72.6%, respectively, in patients with MA. More MA patients benefited from appendicectomy compared with the negative appendicectomy group (82 versus 63%, P = 10 (%)
Neutrophils (%)
Mean Alvarado score out of 10
31.4 48.4 0.000003
28.0 33.0 0.071
60.7 59.3 0.371
96.2 88.2 0.78
14.6 24.9 0.002
7.5 8.1 0.646
32.2 35.3 0.17
27.2 31.7 0.093
4.3 1.8 5.0 1.9 0.000183
N/V, nausea/vomiting; RIF, right iliac fossa; WCC, white cell count.
Table 3 CT and USS findings for histologically positive and negative appendicectomies
Mucosal appendicitis Negative histology Other appendicitis – transmural/gangrenous/ perforated CT, computed tomography; USS, ultrasound scan.
© 2016 Royal Australasian College of Surgeons
CT positive (%)
CT negative (%)
Total CT
USS positive (%)
USS negative (%)
Total USS
7 (25.9) 9 (25.7) 234 (96.7)
20 (74.1) 26 (74.3) 8 (3.3)
27 35 242
37 (27.4) 35 (22.4) 195 (64.8)
98 (72.6) 121 (77.6) 106 (35.2)
135 156 301
4
All patients confirmed to have MA and negative appendicectomies were retrospectively chart reviewed to calculate the Alvarado score. Patients with MA had a statistically significant higher scores (5.0 1.9) compared with patients who had negative appendicectomies (4.3 1.8). This is taking into account that patients with negative appendicectomies had higher incidence of other concurrent pathology (Table S3), and this also reflects the utility of Alvarado score in that it has a higher negative predictive value at lower scores.17 Patients with MA are more likely to report migratory pain (48.4 versus 31.4%, P = 0.000003) and rebound tenderness (24.9 versus 14.6%, P = 0.002). The differences between anorexia, nausea/vomiting, right iliac fossa tenderness, temperature and laboratory findings were not statistically significant. Patients were clinically reviewed post-operatively in the outpatients department. More patients in the MA group were well on follow-up compared with the negative appendicectomy group (82 versus 67%, P = 0.0002). There have been no previous studies examining the utility of CT and USS for MA. The results in this study show that CT and USS generally have a lower detection rate for MA, however, CT has high sensitivity and specificity in cases of transmural appendicitis. A total of 74.1 and 72.6% of MA is undetectable on CT and USS, respectively, therefore a high index of clinical suspicion should lead the clinician to suspect a diagnosis of MA in young female patients with low Alvarado scores, in the absence of other obvious clinical pathologies. On review of coincidental conditions, there was a statistically significant higher proportion of other co-existing pathology in the negative appendicectomy group compared with the MA group (37 versus 18%, P =
