title: Osteochondromatosis in a Rhesus macaque (Macaca mulatta).
abstract: A 5-y-old, male, rhesus macaque (Macaca mulatta) presented with a prominent mass slightly anteriomedial to the right stifle. On exam, multiple radiopaque masses were identified protruding from the mid- and distal femur. Lateral and anteroposterior radiographs of the right stifle  region revealed multiple exophytic masses arising from the femur, with mild bony reaction of the proximal tibia. Histologic examination of biopsy tissue revealed woven and lamellar bone with granulation tissue and skeletal muscle. Because the macaque was exhibiting no lameness or signs of  pain, we decided to monitor the progression of the masses. Minimal change was noted during the time prior to study termination at 6.5 y of age. Necropsy revealed that the bony masses were cartilage-capped lesions arising near the growth plate of the distal femur and midshaft of the femur and  tibia. Histologic examination revealed chondro-osseous exophytic growths that blended imperceptibly with the cortex and spongiosa of the femur, consistent with a final diagnosis of multiple osteochondromas.
authors.affiliation: Department of Animal Resources, Yerkes National Primate Research Center, Atlanta, Georgia, USA.
authors.forename: Kristin A
authors.initials: KA
authors.lastname: Matthews
authors.forename: Karen
authors.initials: K
authors.lastname: Strait
authors.forename: Fawn
authors.initials: F
authors.lastname: Connor-Stroud
authors.forename: Cynthia L
authors.initials: CL
authors.lastname: Courtney
mesh_terms: D000818:Animals; D000830:Animals, Laboratory; D001344:Autopsy / Q000662:veterinary; D001706:Biopsy / Q000662:veterinary; D005266:Femoral Neoplasms / Q000662:veterinary*; D005269:Femur / Q000000981:diagnostic imaging / Q000473:pathology*; D008253:Macaca mulatta; D008297:Male; D008992:Monkey Diseases / Q000175:diagnosis* / Q000473:pathology; D018216:Osteochondromatosis / Q000662:veterinary*; D011859:Radiography; D013997:Time Factors