Abstract
Twenty-five patients with known neuroendocrine tumour disease were biopsied with 1.2 mm and 0.9 mm biopsy-gun needles to evaluate the respective diagnostic accuracy of the 2 needle sizes. the influence of treatment-related fibrosis on the histopathological diagnosis was also evaluated. the overall diagnostic accuracy with the 0.9 mm needle was 69% as compared to 92% with the 1.2 mm needle. This difference, however, seems more related to needle guiding difficulties with the 0.9 mm needle than to insufficient tissue yield. When the tumour was hit with both the 0.9 and the 1.2 mm needle the tissue yield was inferior with the 0.9 mm needle in only one of 16 cases. the increased amount of fibrous tissue due to interferon treatment did not seem to negatively influence the diagnostic accuracy.