Today’s case is an 11 year old Golden Retriever with forelimb lameness. Post your comments below.
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 Case originally posted on December 10, 2009
Teaching and learning about veterinary diagnostic imaging.
Today’s case is an 11 year old Golden Retriever with forelimb lameness. Post your comments below.
Access all images and case information.
 Case originally posted on December 10, 2009
There is a mass effect cranial to the heart on both right and left thoracic radiographs. The mass is better visualized on the right lateral radiograph and does not efface with the cardiac silhouette.
On the VD/DV view, there is increased radiopacity of the left cranial thorax.
Interlober fissures are detectable and have equal thickness in the periphery compared to the hilar region. This could be the result of plural thickening in older patients.
Differential diagnosis should include hypertrophic osteopathy or metastasis to the limb due to primary lung tumor or metastatic lesions.
Fine needle aspiration or biopsy of the lesion is recommended to determine the lesion type. A complete abdominal ultrasound exam can help to spot any possible involvement.
Soft tissue opacity is present in the left cranial thoracic cavity adjacent to the cardiac silhouette. On lateral views, this soft tissue opacity is linear and somewhat irregularly shaped, and it is present around the cranioventral aspect of cardiac silhouette. Pleural fissure lines are noted between right middle and caudal and left cranial and caudal lung lobes.
A small mineral opacity is present over the intertubercular fossa of one of humeri; however, it is not visualized on other views.
Soft tissue opacity in the cranial thorax represents probable thymoma. Pulmonary neoplasia is less likely. CT scan or ultrasound with bx is recommended for further investigation. Pleural fissure lines are likely pleural fibrosis as there are no other obvious signs of pleural effusion.
A mineral opacity in the intertubercular fossa of humerus may indicate bicipital tenosynovitis. Additional radiographs or ultrasound is recommended for acurate evaluation. Lameness may be secondary to possible bicipital tenosynovitis and/or paraneoplastic syndrome of thymoma.
So options we have for this mass are lung tumor and thymoma. Is there evidence for a different origin? It’s located in the left cranial thorax, and there is a distinct separation between it and the mediastinum. Is the cranial mediastinum traveling in a straight line? Where else could it be coming from? I agree, a CT would be a good next step.
Right now I see clear margin of left cranial mediastinum, and the mass is compessing the cranial mediastinum to the right. Also I think there is extrapleural sign on the left cranial thoracic wall related to the mass. It is likely pleural mass…So….I guess I have to take back thymoma from my list.. 🙂
It also appears there may be a component of this mass that is extra-thoracic. The evidence for this appears lateral to left rib 2-3. I looked hard for evidence any ribs might be involved too … except for maybe some subtle displacement of left rib 2/3, I couldn’t see any clear rib involvement.
Dan, that’s a good thought. Since we’ve decided it’s likely extrapleural, it’s worth considering what tissues it might be arising from. Ribs are notoriously tricky to evaluate.
Wow – I guess I should have dragged these images into editing software and looked a little harder. From radiographs, I would not have predicted anywhere near the degree of rib destruction found at CT … amazing.