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Introduction

A strong association exists between gall stone disease (GSD) and GBC but not all patients with GSD develop GBC. The current study was undertaken to find out differences in the non contrast computerized tomographic (NCCT) density of GS in patients with GBC and CC and xanthogranulomatous cholecystitis (XGC).

Material and Methods

Gall bladder specimens and GS were collected and labeled as GBC, XGC or CC based on the histopathology report. For each GBC stone, at least one age matched (+ 5 years) XGC and CC stone was identified and the sample of 95 set of stones (GBC - 30, XGC - 30 and CC - 35) was subjected to evaluation of density by NCCT. Radiologists were blinded for the histopathology findings.

Results

The findings of the stone between the three groups are given in table 1. The GBC stones had a significantly higher maximum density (- 69 HU, range = - 588 to +983 HU) when compared with XGC (- 198 HU, range = - 536 to +132 HU) and CC (- 192 HU, range = - 573 to +532 HU) {p-value 0.04 - GBC vs XGC, 0.007 - GBC vs CC). The minimum density for GBC was - 335 HU (range = - 624 HU to + 250 HU), for XGC was - 422 HU (range = - 746 to - 32), and for CC was - 413 HU (range = - 709 to + 11) (p value NS). NCCT density (cutoff value of -125 HU) could differentiate GBC from XGC with 64% sensitivity, 45% specificity, 62% positive predictive value (PPV) and 47% negative predictive value (NPV). It could differentiate GBC from CC with 64% sensitivity, 85% specificity, 72% PPV and 80% NPV.

Conclusions

Significant differences were found in the CT density of GS in patients with GBC and CC. Thus some GS have a higher risk for GBC than others. CT density of GS can be measured in-vivo in patients with asymptomatic GS and if it suggests GBC - type GS, prophylactic cholecystectomy may be advised for secondary prevention of GBC.

Table 1 Stone findings in three groups

CC - Chronic cholecystitis

GBC - Gall bladder cancer

HU - Hounsfield Units
 XGC - Xanthogranulomatous cholecystitis

98th AACR Annual Meeting-- Apr 14-18, 2007; Los Angeles, CA