New morphological findings in so-called negative appendectomies

Clinical Significance of Variable Histomorphologic Findings Related to Mucosal Inflammation in Negative Appendectomy

The aim of the study was to investigate the clinical significance of various histomorphologic findings related to mucosal inflammation in negative appendectomy. We reviewed histopathologic findings of 118 negative appendectomies and correlated them with the appendicitis inflammatory response (AIR) score and appendiceal diameter. Among 118 patients with negative appendectomy, 94 (80%), 73 (78%) and 89 (75%) patients displayed mucosal inflammation, high neutrophil score (neutrophil count ≥10/5 high power field and surface epithelial flattening, respectively. Out of 118 patients with negative appendectomy, mucosal inflammation, high neutrophil score and surface epithelial flattening were associated with higher risk group according to the appendicitis inflammatory response (AIR) score (p < 0.05, respectively). In addition, mucosal inflammation, high neutrophil score and surface epithelial flattening were frequently detected in 118 negative appendectomies, compared with 24 incidental appendectomies (p < 0.05, respectively). In an analysis of 77 negative appendectomy patients with appendiceal diameter data available, increased appendiceal diameter was positively correlated with luminal inflammation, high neutrophil score and surface epithelial flattening (p < 0.05, respectively). In conclusion, mucosal inflammation, high neutrophil score and surface epithelial flattening in negative appendectomy may be relevant to patients’ signs and symptoms, especially in cases with no other cause of the abdominal pain.

Appendectomy is followed by increased risk of Crohn's disease

BACKGROUND & AIMS

Appendectomy is associated with a low risk of subsequent ulcerative colitis. This study analyzes the risk of Crohn's disease after appendectomy.

METHODS

We followed-up 212,218 patients with appendectomy before age 50 years and a cohort of matched controls, identified from the Swedish Inpatient Register and the nationwide Census, for any subsequent diagnosis of Crohn's disease.

RESULTS

An increased risk of Crohn's disease was found for more than 20 years after appendectomy, with incidence rate ratio 2.11 (95% confidence interval [CI], 1.21-3.79) after perforated appendicitis, 1.85 (95% CI, 1.10-3.18) after nonspecific abdominal pain, 2.15 (95% CI, 1.25-3.80) after mesenteric lymphadenitis, 2.52 (95% CI, 1.43-4.63) after other diagnoses. After nonperforated appendicitis, there was an increased risk among women but not among men (incidence rate ratio 1.37; 95% CI, 1.03-1.85, respectively, 0.89, 95% CI, 0.64-1.24). Patients operated on before age 10 years had a low risk (incidence rate ratio 0.48, 95% CI, 0.23-0.97). Crohn's disease patients with a history of perforated appendicitis had a worse prognosis.

CONCLUSIONS

Appendectomy is associated with an increased risk of Crohn's disease that is dependent on the patient's sex, age, and the diagnosis at operation. The pattern of associations suggests a biologic cause.

The pathology of acute appendicitis

Although acute appendicitis is frequent, it is subject to common misconceptions. Furthermore, there is little good evidence to support some of our beliefs. This report reviews the role of the anatomic pathologist in diagnosis when acute appendicitis is suspected clinically and discusses what is known of its pathology. The conclusions that can be legitimately drawn from the literature are emphasized. A classification is proposed that incorporates intraluminal inflammation, acute mucosal inflammation, acute mucosal and submucosal inflammation, suppurative (phlegmonous) appendicitis, gangrenous appendicitis, and periappendicitis, and the significance of each of these diagnoses is discussed. The etiology and pathogenesis of acute appendicitis is reviewed. Contrary to popular belief, the best evidence indicates that obstruction is unlikely to be the primary cause, at least in the majority of cases. Ancillary techniques in the diagnosis of appendicitis, including laparoscopy and peritoneal aspiration cytology, are discussed.