The Usefulness of Extemporaneous Cytological Examination in Imaging-Guided Biopsies

This study investigates the usefulness of extemporaneous cytological examination performed during imaging-guided biopsies in dogs and cats. In veterinary diagnostics, imaging techniques such as ultrasound and computed tomography are essential for identifying lesions, but they cannot distinguish between inflammatory and neoplastic processes. Biopsies are therefore required, and this study explores whether immediate cytological evaluation of tissue cores, rolled onto slides and examined under a microscope, can help determine sample adequacy and reduce the number of biopsies needed. Seventy-nine animals with soft tissue or bone masses underwent ultrasound or CT-guided biopsies, followed by extemporaneous cytology and histopathological analysis. Cellular material representative of the lesion was identified in 81.1% of cases, allowing clinicians to conclude the procedure without further sampling. The diagnostic accuracy of cytology compared to histology was 68.3%, with particularly high accuracy for lipomas, melanomas, and mast cell tumors. When excluding non-diagnostic samples due to poor preparation or lesion characteristics, the accuracy reaches 92.1%. These findings suggest that extemporaneous cytology is a useful tool for verifying sample adequacy in real time, potentially reducing procedural risks and improving diagnostic efficiency. While histology remains the gold standard, this method offers immediate feedback and may enhance clinical decision-making in veterinary interventional diagnostics.