title: Reactive amyloidosis associated with ischial callosititis: a report with histology of ischial callosities in rhesus macaques (Macaca mulatta).
abstract: Ischial callosities have received little attention in veterinary medicine even though they are distinguishing anatomic organs. The organs are characterized by a pair of hairless pads of thickened epidermis, located bilaterally in the gluteal region, which overlay the tuberosities of the ischia of all Old World monkeys, gibbons, and siamangs. The current report describes a case of reactive amyloidosis associated with ischial callosititis in a rhesus macaque (Macaca mulatta). Amyloid A (AA) protein was found in the liver, spleen, small intestine, mesenteric lymph nodes, and ischial callosities by histology, Congo red stain, and immunohistochemistry. Confocal microscopy showed that many cluster of differentiation (CD)68-positive macrophages within the ischial callosities contained intracellular AA protein, which suggests that CD68-positive macrophages have an important role in the pathogenesis of reactive amyloidosis in nonhuman primates. The normal histology of ischial callosities of rhesus macaques is also documented in this report.
authors.affiliation: Divisions of Comparative Pathology, Tulane National Primate Research Center, Covington, LA, USA. dliu1@tulane.edu
authors.forename: David X
authors.initials: DX
authors.lastname: Liu
authors.forename: Margaret H
authors.initials: MH
authors.lastname: Gilbert
authors.forename: Xiaolei
authors.initials: X
authors.lastname: Wang
authors.forename: Peter J
authors.initials: PJ
authors.lastname: Didier
authors.forename: Ronald S
authors.initials: RS
authors.lastname: Veazey
mesh_terms: D000686:Amyloidosis / Q000473:pathology / Q000662:veterinary*; D000818:Animals; D002145:Callosities / Q000473:pathology*; D008253:Macaca mulatta; D008297:Male; D008992:Monkey Diseases / Q000473:pathology* / Q000628:therapy; D012871:Skin Diseases / Q000473:pathology / Q000662:veterinary*