Diagnostic validity of static telepathology supporting hospitals without local pathologists in low-income countries.

INTRODUCTION: Static telepathology (TP) was used to support a hospital in Tanzania that cannot employ a resident pathologist but has a basic laboratory. Histological slides were prepared by the local technical staff and digital images were uploaded into an Internet-based system; consultant pathologists in Germany could give their opinion. The aim of the study was to examine the diagnostic validity of this project without local pathologists.

METHODS: The set-up period for special training of local technical assistants was 10 weeks. Diagnoses of the first 545 cases that were processed via TP were compared with the results of a second opinion on the basis of routine slides created from the corresponding paraffin blocks, which were sent to Germany.

RESULTS: Of all cases, 384 (70%) TP diagnoses were completely confirmed by the second opinion. Minor deviations (e.g. divergent subtypes of tumours or other aetiology of non-specific reactive processes) were documented in 76 cases (14%), so that overall, 84% of diagnoses were useful in the setting of the available therapeutic possibilities. The results were better in some subgroups of diseases (90-100% useful diagnoses) and suboptimal (minimum 63%) in a few subgroups with rare diseases. Thirty (5%) malignant diseases were primarily misinterpreted as being benign and 12 (2%) benign diseases as malignant. Forty-three (8%) cases were insufficient for diagnosis using TP and could not be provided with a primary assessment.

DISCUSSION: Static TP can help support medical services in low-income countries in the absence of local pathologists with a potentially high diagnostic validity, especially for selected groups of diseases. The procedure can significantly improve the diagnostic procedures before commencement of therapy - a substantial contribution within a globalised world.