Figure 3.

Histological features and immunoreactivity patterns of necrobiotic xanthogranulomatosis (patient 2). Part of the lesion showing (A) fields of necrobiotic collagen and (B) numerous giant cells, mostly of the Touton type (insert: high magnification of a typical example). (C) The accumulation of lymphocytes and a cross section of a nerve bundle in the top right corner of the microphotograph. (D) Staining for CD68 (KP1) revealed that most of the cells surrounding the cholesterol clefts are of monocyte/macrophage lineage. (E) Mast cells scattered between macrophages and lymphocytes showed signs of activation/degranulation as judged by extracellular staining for mast cell tryptase. (F) Staining for IgG κ light chains was seen extracellularly, in plasma cells, and in macrophagic foam cells. (G) Apolipoprotein AI and (H) apolipoprotein B were similarly located (inserts: negative controls). (I) Some macrophages stained for amyloid A. Original magnifications: (A–F), ×140; (G–I) and insert in (B), ×350. Staining: (A–C), haematoxylin and eosin; (A–G) counterstained with Mayer’s haematoxylin; (H, I), no counterstaining.