When the Tests Disagree: The Diagnostic Gap Between Cytology and Histopathology in Canine Splenic Masses

Send us Fan MailA splenic mass shows up on ultrasound and the question hits like a brick: benign or malignant? We go straight at the uncomfortable truth behind canine splenic cytology. Even when splenic FNA feels like the “do something now” step, the match between cytology and histopathology is only moderate, and that has consequences for how we advise families, schedule rechecks, and decide when splenectomy is the safest path.We talk with Drs. Janet Grimes and Matthew Aluisio about what their data means in the exam room: why a neoplastic cytology result tends to be more predictive than a non-neoplastic one, and why a benign aspirate does not rule out cancer. We unpack the spleen’s built-in complexity, including extramedullary hematopoiesis, mixed cell populations, and the sampling problem of trying to summarize a large, heterogeneous lesion from a tiny needle sample. We also get specific about the diagnoses no one wants to miss, including hemangiosarcoma and lymphoma, and how tumor exfoliation and overlap with reactive processes can blur the picture.From there, we shift into action: when cytology is most useful, when serial ultrasound monitoring is a reasonable strategy for smaller, non-ruptured nodules, and when size and rupture risk should move the conversation toward surgery and definitive histopathology. We also dig into the “possibly neoplastic” gray zone and why calling your pathologist can be one of the most practical diagnostic tools you have.If you work up splenic masses in dogs and want clearer owner conversations, better monitoring plans, and fewer false reassurances, this one is for you. Subscribe, share with a colleague, and leave a rating and review so more clinicians can find the show.JAVMA article: https://doi.org/10.2460/javma.26.01.0006INTERESTED IN SUBMITTING YOUR MANUSCRIPT TO JAVMA ®  OR AJVR ® ?JAVMA ® : https://avma.org/JAVMAAuthorsAJVR ® : https://avma.org/AJVRAuthorsFOLLOW US:JAVMA ® :Facebook: Journal of the American Veterinary Medical Association - JAVMA | FacebookInstagram: JAVMA (@avma_javma) • Instagram photos and videosTwitter: JAVMA (@AVMAJAVMA) / Twitter AJVR ® : Facebook: American Journal of Veterinary Research - AJVR | FacebookInstagram: AJVR (@ajvroa) • Instagram photos and videosTwitter: AJVR (@AJVROA) / TwitterJAVMA ®  and AJVR ®  LinkedIn: https://linkedin.com/company/avma-journals