Gallbladder carcinoma and epithelial dysplasia: Appropriate sampling for histopathology

Gallbladder carcinoma (GC) is an uncommon malignancy with an overall 5-year survival of <5%. Due to overlap of clinical presentation with the more common cholecystitis, an estimated 50-65% of all GCs are found incidentally. Epithelial dysplasia is identified in ~50% of specimens with invasive carcinoma. Recent expert panel guidelines have recommended histologic examination of the entire gallbladder in cases where initial sampling reveals dysplasia. 89 cases of GC, 34 high grade dysplasia (HGD), and 60 low grade dysplasia (LGD) were identified in cholecystectomy specimens assessed at our institution over the last 15 years. Pre-operative imaging (either ultrasound or CT) only identified 52% of mass lesions in GC cases. Among gallbladder specimens with epithelial dysplasia only at initial sampling, additional sectioning was performed in 59% of HGD and 55% of LGD. Additional sectioning of gallbladder specimens with HGD had a higher yield (10%) for identifying invasive carcinoma than those with LGD (0 of 28). The diagnostic yield of additional sectioning is significantly higher in the setting of high grade as compared to low grade dysplasia, suggesting that sampling at the discretion of the pathologist may be sufficient for the latter.