The clinical correlation of findings obtained by fine needle fenestration biopsy of the canine spleen with visible ultrasound changes

The medical records databases (March 2016 to March 2021) of the Faculty of Veterinary Medicine, University of Zagreb, were examined to determine the frequency and clinical relevance of cytological diagnoses from fine-needle fenestration biopsy (FNFB) of the spleen in dogs with visible ultrasound changes. Seventy-five dogs were divided into clinically relevant and irrelevant groups, according to the clinical relevance of the diagnosis. The incidence of clinically relevant diagnoses was 28/75 (37.3%). Malignant diagnoses were over-represented (23/28; 82.1%), followed by hemorrhages/hematomas (3/28; 10.7%) and suppurative inflammation (2/28; 7.1%). The most common malignancy was lymphoma (12/28; 42.9%). There was no correlation between the ultrasound lesions examined and the relevant cytological diagnoses, except in cases of patchy echo texture (P = 0.010). Lesion size greater than 1.74 cm had the highest sensitivity/specificity values (91.3%; 42.1%) with a significant area under the curve (AUC) of 0.68 (P = 0.029) for predicting clinically relevant findings. The complication rate due to bleeding was 2/130 (1.5%). In conclusion, splenic FNFB can be safely performed in dogs as it carries a low risk of development of complications. Specific ultrasonographic findings, such as patchy echo texture pattern, may increase the suspicion of the presence of neoplastic disease in the form of lymphoma. According to ROC analysis, lesion size greater than 1.74 increases the possibility of predicting clinically relevant findings.