Synovial Osteochondroma Involving the Elbow of a Cat

Abstract

Practitioners should be alert to the possibility of this benign entity. Misdiagnosis as a chondrosarcoma, for example, might conceivably lead to radical and unnecessary amputation.

Extraskeletal osteochondroma on a cat´s elbow

“…Radiographically, a feline extraskeletal osteochondroma is indistinguishable from a parosteal osteosarcoma, extraskeletal osteosarcoma and an extraskeletal chondrosarcoma, so histopathology is required to confirm the diagnosis (Gradner et al 2008;Tan et al 2010). All can appear in the appendicular soft tissues as bony structures that do not invade the adjacent cortical bone (Gradner et al 2008;Heldmann & Wagner-Mann 2000;Tan et al 2010).…”

“…All can appear in the appendicular soft tissues as bony structures that do not invade the adjacent cortical bone (Gradner et al 2008;Heldmann & Wagner-Mann 2000;Tan et al 2010).…”

“…They are classified according to the number of masses as solitary (solitary osteochondroma) or multiple (osteochondromatosis or multiple cartilaginous exostoses) and as skeletal (axial and appendicular) or extraskeletal, according to the location (Barr 2005;Dernell 2003;Dernell et al 2005;Doige 1987;Gradner et al 2008;Johnson & Watson 2005;Levitin et al 2003;Mahoney & Lamb 1996;McAllister & Tobin 2005;Pool & Carrig 1972;Ranade & Pacchiana 2011;Tan et al 2010;Wood et al 2002). There is also a synovial form that appears as multiple articular mineralised bodies that do not originate from the bone itself, being located within the joint or bursa (Barr 2005;Dernell 2003;Dernell et al 2005;Doige 1987;Gradner et al 2008;Johnson & Watson 2005;Levitin et al 2003;Mahoney & Lamb 1996;McAllister & Tobin 2005;Pool & Carrig 1972;Ranade & Pacchiana 2011;Tan et al 2010;Wood et al 2002).…”

“…Feline osteochondromas are rare entities and those that have been described previously have mainly been skeletal or synovial osteochondromas (Dernell 2003;Dernell et al 2005;Doige 1987;Gradner et al 2008;Levitin et al 2003;Ranade & Pacchiana 2011;Tan et al 2010;Wood et al 2002). Uncommonly, one feline extraskeletal osteochondroma has been reported as a case where several linear masses parallel to long bones with no osseous attachment were evident.…”

Synovial Osteochondroma: An Uncommon Manifestation of a Common Disease

“…4 In this issue of JFMS, Tan et al discuss an illustrative case study of a lame cat with a synovial osteochondroma of the elbow. 8 Although this is an extreme example, less severe variations of this occur commonly in a variety of joints in cats afflicted by osteoarthritis. This condition is thus an uncommon manifestation of a very common disease.…”