Comparison of conventional microscopy and digitized imaging for diagnosis in serous effusions

To compare diagnoses made from conventional microscopy and digitized imaging in preparation for teleconsultation cytopathology services that are affordable and efficient.

One hundred six consecutive serous effusions received in the cytopathology laboratory of a general hospital in Porto Alegre, RS, Brazil, were studied. The diagnoses by the senior cytopathologist at the conventional microscope were considered the standard and identified 61 cases negative and 45 positive for malignant cells (40 epithelial and 5 nonepithelial). The same pathologist digitized 461 selected fields for analysis by a second experienced cytopathologist (observer A) and a senior cytotechnologist (observer B) without knowledge of the standard diagnoses. Ten cases were studied in daily sessions of one hour each. The diagnoses were negative for malignant cells, positive for malignant cells (epithelial) and positive for malignant cells (nonepithelial).

The following kappa values were found: 0.91 (observer A and observer B versus standard) and 0.86 (observer A versus observer B).

Remote digitized imaging diagnosis in serous effusions is possible and has a high degree of concordance with diagnosis by conventional microscopy. Similar studies involving a larger group of cytopathologists and cytotechnologists should be done to identify interobserver variability.