A 55-year-old farmer presents with an irregular, crusted, rapidly growing nodule on the lower lip with a hard, fixed cervical lymph node. Biopsy shows keratin pearl formation with prickle cell layer invasion. What is the most important prognostic factor for this tumor?
- A Location on sun-exposed skin
- B Tumor thickness and depth of invasion ✓
- C Surface ulceration
- D Patient age
Correct answer: B. Tumor thickness and depth of invasion
Explanation
Squamous cell carcinoma (SCC) of the lip is a high-risk location with significant metastatic potential. The most important prognostic factor for SCC is tumor thickness and depth of invasion (Breslow thickness analogy); tumors >2 mm thick or invading beyond the dermis have significantly higher risk of nodal metastasis and recurrence. Perineural invasion is another adverse histological feature. SCCs arising on mucosal surfaces (lip, tongue), in scars, and in immunosuppressed patients carry higher metastatic risk than those on actinically damaged skin.
Reference: Neena Khanna Illustrated Synopsis of Dermatology & STD, 6th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.