Canine Gastrointestinal Spindle Cell Tumors Efficiently Diagnosed by Tissue Microarray-Based Immunohistochemistry

Area of Science:

• Veterinary Pathology
• Oncology
• Immunohistochemistry

Background:

• Canine gastrointestinal spindle cell tumors require accurate classification for diagnosis and treatment.
• Immunohistochemistry is crucial for differentiating tumor types like GIST, SMT, and others.
• Tissue microarray (TMA) offers a method for simultaneous evaluation of multiple samples, potentially saving time and cost.

Purpose of the Study:

• To evaluate the efficacy of TMA in classifying canine gastrointestinal spindle cell tumors.
• To compare TMA-based immunohistochemistry results with full tissue section analysis.
• To assess the diagnostic accuracy of TMA for GIST, SMT, and non-GIST/non-SMT using specific markers.

Main Methods:

• Investigated 34 canine gastrointestinal spindle cell tumor cases using TMA with 2 cores per case.
• Performed immunohistochemistry for α-smooth muscle actin (α-SMA), desmin, and CD117 on both TMAs and full tissue sections.
• Compared the diagnostic concordance between TMA and full section analyses.

Main Results:

• TMA demonstrated high specificity (100%) and sensitivity (93.8% for α-SMA, 80.8% for desmin, 100% for CD117) compared to full sections.
• TMA correctly identified most GISTs (6/6), SMTs (25/26), and non-GIST/non-SMTs (2/2).
• One SMT was misclassified as non-GIST/non-SMT on TMA.

Conclusions:

• TMA-based immunohistochemistry is an efficient and accurate method for diagnosing canine gastrointestinal spindle cell tumors.
• The TMA technique is suitable for large-scale research studies involving canine gastrointestinal tumors.
• TMA facilitates reliable classification of GIST, SMT, and other spindle cell neoplasms in canine GI tract.