Inter-observer variability in the histologic criteria of diagnosis of hydatidiform moles

@#Introduction: In the event of encountering hydropic villi in products of conception specimens, pathologists will have to distinguish complete and partial hydatidiform mole (CHM & PHM) from hydropic abortion (HA). The histological diagnostic criteria are subjective and demonstrate considerable inter-observer variability. Materials and Methods: This study evaluated the inter-observer variability in diagnosis of CHM, PHM and HA according to defined histologic criteria. Ninety abortus conception specimens were reviewed. Representative haematoxylin and eosin-stained slides were assigned independently to two pathologists who were asked to make a diagnosis of CHM, PHM or HA, and provide a report of the identified diagnostic histological criteria. Kappa value was calculated for the inter-observer agreement. Results: There was a total of 36.7% disagreement between two pathologists (K = 0.403, Strength of Agreement = moderate), of which 24.4% and 12.2%, were differentiating PHM from CHM and PHM from HA, respectively. Among defined diagnostic histological criteria, the highest rate of agreement was observed in the identification of cistern formation and hydropic changes (K = 0.746 and 0.686 respectively, Strength of Agreement = substantial). Conclusion: There was moderate to substantial agreement rate between two pathologists in identification of two essential histologic criteria for diagnosis of molar pregnancies i.e. “hydropic change” and “trophoblastic proliferation”.

H. pylori infection and the correlation to chronic active gastritis detected by the histological criteria of the sydney system.

In Thailand, chronic active gastritis and chronic atrophic gastritis have not been given frequent mention. Our aim is to present the relationships of the many variables in histological classification of chronic bacterial gastritis by the Sydney System. This paper presents the prevalence of chronic active gastritis by studying the degree of H. pylori infection detected by the Modified Toluidine Blue staining (MTBs) and histological grading, using the Sydney System. A total of 355 dyspeptic patients who underwent endoscopy in Kawila hospital, Chiang Mai, northern Thailand from January 1996 to January 1998, were included in the study. Overall, 284 patients (80.3 %) had an H. pylori infection. Diagnosis varied from normal, chronic gastritis, and acute gastritis to chronic active gastritis in 11 (3.1 %), 95 (26.8 %), 0 (0 %), 249 (70.1 %) patients respectively. Sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of neutrophils presented with lymphocytes are 85.2, 90.1, 97.2, and 60.4 %, respectively. We conclude from the study that chronic active gastritis is a very common condition in Thailand. If chronic active gastritis is present, H. pylori is usually detected, and the degree of infection is well correlated to the degree of inflammation.