Necrobiosis lipoidica diabeticorum (NLD) most characteristically affects which anatomical site and shows which histological pattern?
- A Dorsal hands; sarcoidal granuloma without necrobiosis
- B Shins; palisading granuloma with necrobiosis of collagen and plasma cell infiltrate ✓
- C Trunk; palisading granuloma of elastin fibres
- D Periorbital area; xanthomatous foam cells with no granuloma
Correct answer: B. Shins; palisading granuloma with necrobiosis of collagen and plasma cell infiltrate
Explanation
NLD classically presents on the pretibial shins as waxy yellow-brown atrophic plaques with telangiectasia. Histology shows full-thickness dermal necrobiosis (degenerated collagen) arranged in horizontal tiers with palisading histiocytes, plasma cells, and a lymphohistiocytic infiltrate — a 'tiered' or 'layer-cake' pattern. Only ~60% of NLD patients have diabetes; conversely, <1% of diabetics develop NLD.
Reference: Neena Khanna Illustrated Synopsis of Dermatology & STD, 6th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
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