Investigation of neutrophil extracellular traps in canine soft tissue sarcomas

This study aimed to explore the relationship between tumor grade and neutrophil extracellular traps (NETs) in canine soft tissue sarcomas. For this purpose, 30 soft tissue tumor blocks were utilized. Following the histopathological classification of cases, tumors were categorized as fibrous tissue tumors, adipose tissue tumors, muscle tissue tumors, vascular tumors, peripheral nerve sheath tumors, and vascular wall tumors. Tumors were classified as either benign or malignant. To detect the presence of NETs in tumor tissue, sections were stained using citrullinated histone-3 (cith3) and myeloperoxidase antibodies. The staining was performed on the same sections using a fading and restaining method. The stained sections were then colorized with a program, overlaid, and pseudo-immunofluorescent images were obtained. The presence of cith3-positive areas was used to score NETs in tumor tissue and compare them with tumor grade. The study included cases diagnosed with fibroma, leiomyoma, fibromyxosarcoma, fibrosarcoma, hemangiosarcoma, liposarcoma, malignant fibrous histiocytoma, myxosarcoma, perivascular wall tumor, peripheral nerve sheath tumor, and undifferentiated sarcoma. The cases were classified based on tumor grade, and subsequently, statistical comparisons were conducted among the groups, revealing a numerical increase in grade III tumors compared to grades I and II tumors, but no significant difference in NETs. The Pearson correlation analysis was conducted to examine the relationship between NETs and mitosis, differentiation, necrosis, and tumor grade. The correlation between NETs and tumor grade was found to be insignificant (r = 0.277). Similarly, correlations between mitosis, differentiation, and necrosis with NETs were also found to be insignificant. The study results indicate that NETs were significantly higher in soft tissue sarcomas compared to benign tumors. Moreover, when sarcomas were graded histologically, the presence of NETs was slightly higher in grade III tumours, but this difference was not statistically significant compared to grades I and II tumours. Furthermore, the study found no significant correlation between NET scores and necrosis, differentiation, mitosis, and tumour grade in sarcomas.