Clinical/pathological analysis of gallbladder adenomyomatosis; type and pathogenesis

Abstract

Background/aims: The aim of this study was to analyze the clinical/pathological outcomes of patients that underwent surgery for gallbladder adenomyomatosis, to clarify the characteristics of the type and pathogenesis of adenomyomatosis.

Methodology: From May 1997 to March 2008, 4704 consecutive patients underwent cholecystectomy at Ajou University Medical Center. Among them, 113 (2.4%) patients that were histopathologically diagnosed with adenomyomatosis or adenomatous hyperplasia were selected for this study. The patients were divided into a fundal type group and a segmental/diffuse type group, and the specimens reviewed with Hematoxylin-Eosin (H & E) and immunohistochemical stainings.

Results: Sixty-three patients were male and 50 female; the age ranged from 17 to 76 years of age. The fundal type was the most common type. Gallstones were present in 69.9% of the patients. In the analysis of the fundal and segmental/diffuse types, gallstones were present in 23 patients with fundal type and in 53 patients with segmental/diffuse type; this difference was statistically significant (p < 0.05). Review of H & E staining showed that the most common findings were grade 1 (n = 14) in the fundal type and grade 2 (n = 23) in the segmental/diffuse type; there was a significant difference in the inflammatory grade (p < 0.05). Immunohistochemical staining showed expression of vimentin, as a mesenchymal marker in 28.0% of cases (n = 16).

Conclusions: The fundal type differed from the segmental/diffuse type based on the clinical/ pathological features; it had a lower frequency of gallstones and a lower inflammatory grade. In addition, no cancer was identified in the resected gallbladders of patients with adenomyomatosis. The findings suggest that the Rokitansky-Aschoff sinuses (RAS) were associated with acquired motility, based on the expression of vimentin, consistent with an epithelial-mesenchymal transition.