A 35 year female comes with Size 5 cm tumour of the oral cavity + single lymph node of 2 cm diameter on the same side in the neck is staged as
**Core Concept**
The question is testing the student's understanding of the TNM staging system for oral cavity cancer. The TNM system evaluates the size of the primary tumor (T), the presence and extent of regional lymph node metastasis (N), and the presence of distant metastasis (M). For oral cavity cancer, the staging of the primary tumor (T) is based on its size, while the staging of the lymph nodes (N) is based on the number and size of the lymph nodes involved.
**Why the Correct Answer is Right**
The correct staging of the primary tumor (T) is based on its size, which is given as 5 cm. According to the TNM staging system, a tumor of 4 cm or smaller is classified as T1, while a tumor larger than 4 cm but not larger than 6 cm is classified as T2. Therefore, the correct staging of the primary tumor is T2. Additionally, the presence of a single lymph node of 2 cm diameter on the same side in the neck indicates N1 staging, as it represents a single lymph node metastasis.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because it does not accurately reflect the T and N staging of the patient's oral cavity cancer.
**Option B:** This option is incorrect because it does not accurately reflect the T and N staging of the patient's oral cavity cancer.
**Option D:** This option is incorrect because it does not accurately reflect the T and N staging of the patient's oral cavity cancer.
**Clinical Pearl / High-Yield Fact**
The TNM staging system is a widely used classification system for cancer staging, and it is used to determine the prognosis and treatment plan for patients with cancer. It is essential for medical professionals to understand the TNM system to accurately stage and manage patients with cancer.
**Correct Answer: C. T2 N1.**