A 45-year-old man with a betel quid chewing habit presents with a 3.5 cm ulcerative growth of the left buccal mucosa invading the adjacent mandible with cortical erosion. There is no involvement of the masticator space or skull base. According to AJCC 8th edition, the T category of this buccal mucosa carcinoma is:
- A T2
- B T4a ✓
- C T3
- D T4b
Correct answer: B. T4a
Explanation
AJCC 8th edition classifies oral cavity tumors with deep invasion into bone cortex as T4a. Cortical erosion of the mandible qualifies as invasion of adjacent structures, placing it in T4a. T4b requires involvement of the masticator space, pterygoid plates, or skull base, which are not present here. T2 applies to tumors 2-4 cm without deep invasion, and T3 applies to tumors >4 cm or depth of invasion >10 mm without bone invasion.
Reference: AJCC Cancer Staging Manual, 8th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.