Tissue architecture of tonsillar tissue in control and MPS I patient.

Haematoxylin and eosin staining demonstrates lymphoid architecture with (A) low and (B) high power fields of view. G.C, germinal centre, composed of follicular dendritic cells, antigen presenting cells and B-cells; M.Z, mantle zone, composed of a rim of T lymphocytes; I.F.Z, interfollicular zone, containing hyalinsed vascular network of arterioles (yellow arrow); squamous crypt epithelium (white arrow); tingible body macrophages (arrowhead). (C) High power field of view of the subepithelial layer in control patient. (D) Equivalent field of view with magnified inset of subepithelial layer in an MPS I patient, demonstrating histiocytoid cell forms (red arrow). Scale bars represent 100μm except in magnified inset in D (50μm).