In the histopathology of lupus vulgaris (cutaneous TB), the characteristic finding is:

• A Palisading granuloma with central caseation and plasma cells
• B Naked tubercles of epithelioid cells without caseation (sarcoid-like)
• C Dermal foam cells (Virchow cells) and numerous AFB
• D Tuberculoid granulomata with Langhans giant cells, central caseation, and overlying epidermal atrophy ✓

Explanation

Lupus vulgaris shows well-formed tuberculoid granulomata with Langhans giant cells and central caseation (unlike sarcoidosis which has 'naked' non-caseating granulomata). The overlying epidermis is atrophic or ulcerated. AFB are sparse or absent due to high host immunity (tuberculin strongly positive). The 'apple jelly' nodules seen clinically on diascopy correspond to these granulomata. In contrast, lepromatous leprosy shows foam cells (Virchow cells) with numerous AFB.

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.