How reliable are general histopathologists in detection of helicobacter pylori on routine histology?

Abstract

Background: Many studies agree that routine histology is less sensitive and less specific than special stains and immunohistochemistry (IHC) with false-positive and false-negative rates. Objectives: The aim was to evaluate the accuracy of four general histopathologists in documenting Helicobacter pylori (Hp) bacteria in gastric biopsies (stained with H and E) by using IHC and modified Giemsa stain (MG), also to assess the specificity of MG and whether it can replace IHC. Materials and Methods: Twenty seven reported gastric biopsies were collected from each of four pathologists (9 reported as negative for Hp, 9 reported as scant Hp, and 9 as abundant Hp). The pathologists selected were known to have different thresholds for Hp. The biopsies were stained with MG and IHC and they were read by two pathologists. Results: The four pathologists showed different thresholds for labeling luminal gastric pits' structures as Hp. Overall, there were 5/36 false-negative cases (13.9%) and 26/72 false-positive cases (36%), most of them in the category reported as scant Hp detected. The results of MG were concordant with that of IHC in 107/108 cases. Conclusion: The overall accuracy rate of Hp detection on routine histology was 71%; false positivity was much more common than false negativity, especially when only scant Hp reported to be present. MG is a reliable stain and if done properly, it can replace the more costly IHC. When Hp identification is crucial from the clinical management of view, special stains and/or IHC should be requested.

Keywords

• gastritis
• helicobacter pylori
• immunohistochemistry
• modified giemsa stain
• routine histology