Multiple preoperative biopsies may increase histologic grade accuracy in canine soft tissue sarcoma: a prospective...

Area of Science:

• Veterinary Oncology
• Surgical Pathology
• Canine Neoplasia

Background:

• Canine soft tissue sarcomas (STS) are mesenchymal tumors requiring accurate histologic grading for treatment planning.
• Pre-surgical biopsies are crucial for prognostication, but concordance with final histology is suboptimal (around 59%).
• The impact of increasing biopsy numbers on improving diagnostic accuracy for STS remains unclear.

Purpose of the Study:

• To evaluate if obtaining multiple tumor biopsies influences concordance with definitive STS histology.
• To determine the optimal number and location of biopsies for accurate STS grading.
• To assess the impact of biopsy location (central vs. peripheral) on underestimation of definitive STS grade.

Main Methods:

• Prospective enrollment of 32 client-owned dogs with cutaneous or subcutaneous STS.
• Collection of three punch biopsies (central and two peripheral) post-surgical removal.
• Histologic evaluation of incisional biopsies and whole tumor mass for grading and concordance analysis.

Main Results:

• Concordance between single biopsy and definitive histology varied by location: 71% for central and 59% for peripheral.
• Peripheral biopsies underestimated definitive STS grade in 40.5% of cases; central biopsies underestimated in 29%.
• Taking at least two biopsies (peripheral and central) improved the prediction of definitive STS grade.

Conclusions:

• Biopsy location significantly impacts the accuracy of pre-surgical STS grading.
• Multiple biopsies, strategically sampled from central and peripheral tumor regions, enhance the reliability of STS prognostication.
• Optimizing biopsy techniques can improve treatment planning and outcomes for dogs with soft tissue sarcomas.