The relevance of prognostic factors for canine gastrointestinal soft tissue tumors

Non-angiogenic, non-lymphogenic intestinal mesenchymal tumors (NIMTs) are a diverse group of gastrointestinal neoplasms in dogs, the most common being leiomyosarcomas (LMSAs) and gastrointestinal stromal tumors (GISTs). Advances in immunohistochemical (IHC) techniques, particularly the use of markers like CD117 (c-Kit) and Discovered-on-GIST 1 (DOG-1), have led to more accurate diagnoses and a rise in GIST identification. This study evaluated histopathological and immunohistochemical parameters of 18 canine NIMT using Whole-Slide Imaging, and comparing the findings with clinical outcomes. Although the small sample size limited statistical significance, several results were consistent with previous research. A key finding was the reclassification of seven tumors from LMSAs to GISTs, which underscores the essential role of IHC in differential diagnosis. Additionally, the study found that GISTs had higher mitotic counts (MC) than LMSAs, aligning with earlier studies linking elevated MC with increased metastatic risk and reduced survival. While a threshold of MC ≥2 was highly sensitive and specific for predicting tumor-related death within one year, statistical significance was not reached. Overall, the study reinforces the importance of IHC and MC in diagnosing and assessing prognosis in canine NIMTs, while noting that classification and treatment strategies remain areas of ongoing research.