Pathology A 3 cm squamous cell carcinoma of the retrornolar trigone and invading the mandible and the medial pterygoid muscle is at what TNM stage: A Stage I B Stage II C Stage III D Stage IV 💡 Explanation A 3 cm squamous cell carcinoma of the retrornolar trigone and invading the mandible and the medial pterygoid muscle is at what TNM stage: ✓ Correct Answer: D. Stage IV