Endoscopic findings of gallbladder lesions evaluated with image-enhanced endoscopy: A preliminary study using resected gallbladders

Abstract

The diagnosis of gallbladder (GB) lesions relies on imaging findings. Transpapillary cholangioscopy can potentially be used to diagnose GB lesions; however, the images obtained remain unclear. This study aimed to characterize the endoscopic findings of GB lesions. We examined the endoscopic features of GB lesions in 50 consecutive patients who underwent cholecystectomy. GB specimens were obtained immediately following cholecystectomy, opened on the side opposite the liver bed, and flushed with saline solution. Each lesion was assessed using a high-resolution endoscope equipped with white light and narrow-band imaging magnification. For elevated lesions, both the surface structure (classified as regular, irregular, or absent) and vascular structure (dilation, meandering, caliber change, non-uniformity, and loose vessel areas) were assessed. Twelve of the 50 patients had elevated lesions, including cholesterol polyp (n = 4), hyperplastic polyp (n = 1), xanthogranulomatous cholecystitis (n = 1), and GB carcinoma (n = 6). Advanced GB carcinoma, as opposed to T1 GB carcinoma, demonstrated a papillary surface with destructive areas and neovascularization on narrow-band imaging magnification. Endoscopic images of each GB lesion were characterized, and the differences between GB carcinomas and benign lesions were identified. This preliminary classification may contribute to innovative imaging diagnosis and targeted biopsy for diagnosing GB lesions under direct vision.

Keywords: cholecystectomy; diagnosis; endoscopy; gallbladder; image‐enhanced endoscopy.

FIGURE 1

Endoscopic findings of benign gallbladder (GB) lesions. Normal GB: (a) Mucosa showing the regular arrangement of a low‐height columnar epithelial surface structure under white light imaging (WLI). (b) Narrow‐band imaging (NBI) magnification showing regular vascularity without dilation. (c) Histopathological examination confirming no specific inflammatory or neoplastic lesions. Adenomyomatosis of the GB: (d) WLI showing a regular arrangement of columnar epithelium similar to that of a normal GB. (e) Under NBI magnification, the epithelium is taller than that of normal GB. (f) Histopathological examination confirming adenomyomatosis characterized by dilated ducts and smooth muscle. Cholecystolithiasis: (g) WLI showing areas of redness due to vasodilation. (h) NBI magnification showing slightly dilated regular vessels. (i) Histopathological examination revealing mucosal thinning, wall fibrosis, and mild inflammation with lymphocyte accumulation.

FIGURE 2

Endoscopic findings of benign elevated lesions. Cholesterol polyp: (a) White light imaging (WLI) showing a yellowish, spherical, elevated lesion with a thin stalk. (b) Narrow‐band imaging (NBI) showing regular vessels without dilation. (c) Histopathological examination showing the lesion covered by non‐dysplastic epithelium, with foam histiocytes infiltrating the interstitium. Hyperplastic polyp: (d) WLI revealing a slightly reddish elevated lesion. (e) NBI magnification showing a regular surface structure but a wide intervening part and slight vascular dilatation. (f) Histopathological examination revealing hyperplastic changes in the ductal epithelium and an increased number of capillaries. Xanthogranulomatous cholecystitis: (g) Under WLI, white and brown tones were noticeable in the ulcer‐scarred area and the nonstructural area where the mucosal epithelium had sloughed off. (h) Under NBI magnification, scarring was observed in areas with an intact surface structure, accompanied by numerous uniformly dilated blood vessels with irregular vascular distributions. (i) Histopathological examination confirming the fibrous thickening of the gallbladder wall, clusters of pigment‐phagocytosing histiocytes, granular inflammatory changes, and abscess formation.

FIGURE 3

Endoscopic findings of gallbladder carcinomas. T1a gallbladder carcinoma (GBC): (a) White light imaging (WLI) revealing an elevated lesion with a thick stalk. (b) Narrow‐band imaging (NBI) magnification showing that the surface structure was papillary and the vascular structure was caliber changes with an irregular distribution of blood vessels. (c) Histopathological examination revealing atypical cells with tubular proliferation in the pedunculated lesion, with no invasion of the muscularis mucosae observed. T1b GBC: (d) WLI showing a nodular elevated lesion with an irregular papillary surface structure. (e) NBI magnification revealing caliber changes with an irregular distribution of vessels, which were slightly more dilated than those observed in T1a GBC. (f) Histopathological examination revealing that the adenocarcinoma had infiltrated the muscularis propria of the GB but showed no subserosal invasion. T2 GBC: (g) WLI showing a large elevated lesion with a papillary surface structure, although some areas were non‐structured. (h) NBI magnification revealing neovascularization and greater vascular disparity than T1 GBCs. (i) Histopathological examination revealing an adenocarcinoma with small‐ to medium‐sized tubular infiltration extending into the subserosa. T3 GBC: (j) WLI showing a large, partially submucosal, tumor‐like nodule. (k) NBI magnification revealing irregular vessel images with neovascularization and destructive vessels. (l) Histopathological examination revealing a tubular adenocarcinoma proliferated invasively into the liver parenchyma.