Range of manifestations of amyloidosis in growth factor–deficient mice. (A) Moderate (grade 2) splenic amyloid in an infected 50-week-old female G−/− mouse demonstrating the usual pattern of perifollicular localization of homogeneous acellular eosinophilic material with relative preservation of the splenic white pulp (original magnification ×340, H & E). (B) Extensive (grade 3) confluent splenic amyloid deposits in a 67-week-old female G−/−GM−/− animal with residual atrophic lymphoid follicles (arrows). The mouse was culled due to the presence of a soft-tissue abscess that grew S aureus (original magnification ×340, H & E). (C) Congo red positively stained hepatic amyloid deposition around the central vein in an 81-week-old female G−/−GM−/− mouse (original magnification ×1,360, Congo red). (D) Intestinal amyloid within the submucosa of villi showing characteristic green birefringence when viewed under crossed polarizing filters (same animal as C); original magnification ×1,360, Congo red). (E) Renal amyloid resulting in obliteration of the normal glomerular vasculature in a 48-week-old male G−/−GM−/− mouse (original magnification ×1,360, H & E).