12-year-old, Male, Neutered, Golden Retriever

This case was presented in our Virtual IDEXX Diagnostic Imaging CE event, Summer of 2020.

History: Firm non-painful mass along left thoracic wall. Recently started coughing—dry and non-productive


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How did we grade this during the CE event?

Large, sharply marginated, ovoid, mixed soft tissue and mineral opacity mass within left caudal thorax causing a mediastinal shift to the right and caudal displacement of the left crus of the diaphragm and widening of the left 6th intercostal space2
Mixed lytic and productive lesion of left 7th rib with a large amount of amorphous periosteal reaction that extends both into the thoracic cavity and into the left thoracic wall soft tissues2
Smooth periosteal new bone along left 6th rib1
Generalized hepatomegaly0.5
Thin linear and curvilinear metal opacity structures in stomach0.5
Multifocal spondylosis deformans0
Mass originating from left 7th rib: primary neoplasia of rib.  Sarcoma (osteosarcoma, fibrosarcoma, chondrosarcoma, etc.) most likely.3
Hepatomegaly: nonspecific—endocrine disease, nodular regeneration, neoplasia, or hepatitis.0.5
Gastric foreign bodies0.5

Diagnosis: Primary osseous neoplasia of rib

A brief discussion on this case:

Though this mass has a very large intrathoracic component which may lead one to consider a pulmonary mass, such as a pulmonary carcinoma, as a differential for this case, the presence of aggressive left sided rib changes, particularly the degree of osteolysis of the left 7th rib, is consistent with a body wall mass (specifically for this patient a primary rib tumor – chondrosarcoma and osteosarcoma most commonly) with intrathoracic extension.

Photo by Chris Henry on Unsplash

One comment

  1. Interesting case! I have had a similar one that presented for heavy panting. I have the images and can share. Interestingly enough it was also the 7th rib that the mass originated from.

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