Xanthogranulomatous cholecystitis mimicking gallbladder carcinoma

Figure 1 Histologic features of xanthogranulomatous cholecystitis. A: Low-power view showing an irregularly and unevenly thickened gallbladder wall in a case of xanthogranulomatous cholecystitis; B: The perimuscular soft tissues show a dense inflammatory infiltrate predominantly composed of numerous foamy histiocytes and lymphocytes. No Michaelis-Gutmann bodies, which are characteristic of malakoplakia, are identified; C: In addition to the inflammatory infiltrate, fibroblasts and fibrotic tissue displaying a vaguely storiform pattern are present (right side), potentially posing diagnostic challenges with neoplastic diseases; D: CD68 (PGM1) immunohistochemical staining highlights the predominant histiocytic component.

Figure 2 Multimodal preoperative imaging of xanthogranulomatous cholecystitis mimicking gallbladder carcinoma. A and B: Contrast-enhanced computed tomography in the portal venous and arterial phases showing marked irregular thickening of the gallbladder wall and loss of the cleavage plane with the adjacent liver parenchyma; C: Diffusion-weighted magnetic resonance imaging demonstrating marked diffusion restriction in the gallbladder body-fundus region, further raising suspicion for a neoplastic lesion; D: T2-weighted magnetic resonance imaging showing abnormal gallbladder wall thickening and pericholecystic inflammatory changes, with poor demarcation from the adjacent hepatic parenchyma.