FIG. 2.

Representative pancreatic sections stained for insulin (brown) and hematoxylin from case 1, aged 2.5 weeks (Table 1) (A–C) and case 2, aged 10 weeks (D–F), In early infancy, β-cells were abundant as small clusters (A, objective ×20) surrounded by a single cell layer nonfibrous capsule. In other areas, β-cells were mostly present as single cells (B, objective ×20), shown in high power in C (objective ×100). By 10 weeks of age, the small clusters of β-cells had grown in size and typically occupied an encapsulated islet-like structure, with the β-cells being predominantly polar within the islet as previously described (D, objective ×10; F, objective ×20). The capsule by 10 weeks had some fibrous tissue. At 10 weeks of age, islets were densely located throughout the pancreas but in higher density in some locations (E, objective ×20), in this case decorating a ductal tree.