A 52-year-old man has thick, hyperkeratotic, intensely pruritic violaceous plaques over both shins for three years, unresponsive to potent topical steroids. There is no nail or mucosal involvement. Biopsy is advised primarily to exclude:
- A Basal cell carcinoma
- B Squamous cell carcinoma ✓
- C Kaposi sarcoma
- D Amelanotic melanoma
Correct answer: B. Squamous cell carcinoma
Explanation
Hypertrophic lichen planus typically affects the pretibial skin of middle-aged and elderly patients, producing verrucous, itchy plaques that mimic squamous cell carcinoma clinically. Because long-standing hypertrophic LP itself carries a small risk of malignant transformation, biopsy is essential when the lesion is atypical or refractory. Basal cell carcinoma and melanoma do not present as bilateral symmetrical hyperkeratotic plaques on both shins.
Reference: Rook's Textbook of Dermatology, 9th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
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