Although the incidence of AA appears to have been waning slightly over the past few decades, it remains a frequent cause of acute abdominal pain and urgent operative intervention. The analysis of a patient with possible appendicitis can be divided into 3 parts: history, physical examination, and routine laboratory and radiological tests. The pain was reported in 456 (100%) of our cases which was mostly localized than generalized and mostly more than 12 hours. In this respect, Mughal and Soomro
 have noted pain in 66.7% of patients while, Soomro
 reported abdominal pain in 98.27% of appendicitis patients. Pain involves whole abdomen when there is perforation leading to peritonitis
. This was also true in this series as in complicated appendicitis; generalized pain was more than in normal or inflamed appendicitis. In our cases, second most common presenting symptom was vomiting 76.8% followed by anorexia72.9%, nausea 55.0%, fever 49.1%, diarrhea 4.8% then dysuea 3.1%. Salari and Binesh
 reported anorexia in 84.48% of patients in pediatric age group while, Soomro
 reported anorexia in 86.20% of patients. At operation, we found 29 (6.4%) patients with normal appendix, 350 (76.8%) with inflamed appendix, 77 (16.9%) with complicated appendix. Soomro
 reported that at operation 31 (53.44%) patients with simple appendicitis and 26 (44.82%) patients with complicated appendicitis. In literature the rate of perforated and gangrenous appendicitis has been quoted as 16-57%
Acute appendicitis remains a challenging diagnosis. Almost one-third of patients have atypical clinical features. The wide use of ultra sonography and computer tomography scan has not effectively decreased the rate of perforated appendicitis or number of negative appendectomies in large population studies
 despite the hopeful results of some case series in tertiary care academic hospitals
[1, 17]. Some authors have assessed the diagnostic value of inflammatory markers with varied designs and results
[7, 18–20]. Variety of designs explains the lack of evidence in the two meta-analysis published to date about inflammatory markers diagnostic utility
[9, 21]. Although, over the last few decades, several inflammation markers have been proposed to increase diagnostic accuracy in AA including phospholipase A2,
 amyloid A,
 leukocyte elastase,
 neutrophil count,
 several interleukins and cytokines,
 WBCs and neutrophil counts are certainly the most widely used.
In this study, WBCs and neutrophil counts were significantly higher in patients with inflamed and complicated than normal appendix and in complicated than inflamed appendix. Several reports suggest that an elevated leukocyte count is usually the earliest laboratory test to indicate appendiceal inflammation, and most of the patients with acute appendicitis present with leukocytosis
 despite several studies that acknowledge the limitations of this test
[26, 27]. Sack et al.
.found that WBCs count was clearly elevated in children with phlegmonous and perforated appendicitis. Mughal and Soomro
 found total leucocytes and neutrophil counts elevated in all their patients. Soomro
 reported elevation of total leucocytes and neutrophils counts in 53.33% of their patients. Meanwhile, Yokoyama et al.
 reported that WBCs counts and neutrophil percentage are not useful for surgical indication.
Previous studies assessing the relationship between WBCs count and appendicitis have their findings reported in a variety of ways, including comparing mean values for total WBCs count in patients with and without appendicitis, and variously using P-values, sensitivity, specificity, PPV and NPV
[23, 30]. These studies can be difficult to interpret, because both PPV and NPV depend on disease prevalence. Moreover, sensitivity and specificity alone do not allow clinicians to directly apply diagnostic tests results to individual patients. Grönroos et al.
 were the first to report that an increased leukocyte count was a very early marker of appendiceal inflammation in adult patients, according to ROC analysis. Contrary to descriptive and comparing statistical methods, analysis of ROC curves allows the estimation and verification of diagnostic suitability of diagnostic parameters. LR(+) is defined as the true-positive rate over the false-positive rate. It allows the clinician to assess the likelihood that a patient with a given test result (i.e., elevated WBCs count) has that disease. Additionally, LR is independent of disease prevalence. Generally, a clinically useful diagnostic test has an LR >10 or <0.1.
In this study, cut-off values, at which greatest sum of sensitivity and specificity was obtained, in WBCs and neutrophils counts were (9.400×103 and 7.540×103, respectively) in all patients with appendicitis versus normal appendix. At these cutoff points, AUC (95% CI) for WBCs and neutrophils were 0.701 (standard error, 0.055; 95% CI = 0.671-0.755) and 0.680 (standard error, 0.055; 95% CI = 0.635-0.722). WBCs and neutrophils sensitivity were 76.81%, 70.96%, specificity 65.52%, 65.52%, PPV 97.0%, 96.8%, NPV 16.1%, 13.3%, LR(+) 2.23, 2.06 and LR(−) 0.35, 0.44. Meanwhile, when we took only cases with inflamed appendicitis versus normal appendix, cut-off values in WBCs and neutrophils counts were 9.400 ×103 and 8.080 ×103, respectively. At these cutoff points, AUC (95% CI) for WBCs and neutrophils were 0.704 (standard error, 0.055; 95% CI = 0.655-0.749) and 0.664 (standard error, 0.056 95% CI = 0.614-0.712). WBCs and neutrophils sensitivity were 75.43%, 65.43%, specificity 65.52%, 68.97%, PPV 96.4%, 96.2%, NPV 18.1%, 14.2%, LR(+) 2.19, 2.11 and LR(−) 0.38, 0.50. While, when we took only cases with complicated appendicitis versus normal appendix, cut-off values in WBCs and neutrophils counts were 11.100 ×103 and 7.540 ×103, respectively. At these cutoff points, AUC (95% CI) for WBCs and neutrophils were 0.763 (standard error, 0.058; 95% CI = 0.670 - 0.840) and 0.749 (standard error, 0.060; 95% CI = 0.656 - 0.828). WBCs and neutrophils sensitivity were 76.62%, 81.82%, specificity 72.41%, 65.52%, PPV 88.10%, 86.30%, NPV 53.80%, 57.60%, LR(+) 2.78, 2.37 and LR(−) 0.32, 0.28. ROC curve analysis of our data suggests that there is no value of WBCs or neutrophils counts that is sensitive and specific enough to be clinically useful. An ideal test has an AUC of 1, while a perfectly random test has an AUC of 0.5. Generally, a “good” test has an AUC >0.8 and an “excellent” test has an AUC >0.9. In this respect, it had been reported that inflammatory markers such as WBCs is poorly reliable in confirming the presence of AA because of their low specificity in adults and children
[2, 7, 31]. Sensitivity and specificity for WBCs count determined in this study is comparable with various national
[32, 33] and international
[6, 33–35] studies in which sensitivity ranges from 80.0–88.7%, while specificity ranges from 61.5-87.0%. So, leukocyte count by itself is not completely preventive against negative appendectomy, a finding consistent with our results.
Other investigators have constructed ROC curves for WBCs count and appendicitis with similar results. Körner et al.
 found AUC of 0.69 (95% CI = 0.65-0.73), statistically no different from our results. Grönroos et al.
 found a AUC of 0.730 (standard error = 0.041). Rodriguez- Sanjuan et al.
 found an AUC of 0.67 (standard error = 0.08) for WBCs count and appendicitis in children. Paajanen et al.
 found an AUC of 0.76. Andersson et al.
 found an AUC of 0.80 (standard error = 0.02) for patients admitted to hospital for suspected appendicitis. An elevated total WBCs count might erroneously lead a surgeon to operate when other features of clinical scenario do not warrant or alternatively delay intervention as a result of a normal WBCs count. In support, of Guss and Richards
 showed an association between delay in operative intervention and higher rate of perforated appendix in patients presenting to emergency with eventual diagnosis of appendicitis and normal WBCs count.
The main limitation of this study that it is retrospective so there is biases in inclusion criteria of the patients which included all patients who underwent appendectomy, another prospective study containing all patients with abdominal pain with suspension of appendicitis must be made.