Magnetic resonance imaging findings of a metastatic chemodectoma in a dog : clinical communication

Abstract

A 6-year-old, male, Collie-cross was presented with a non-weight bearing right thoracic limb lameness, right m.deltoideus, m.infraspinatus and m.supraspinatus atrophy, and severe neck pain with spasm of the cervical epaxial muscles. MRI revealed complete destruction of the 5th and 6th cervical vertebral bodies with lateral extradural spinal cord compression at the level of the 4th and 5th cervical vertebrae. These lesions were very clearly demonstrated on magnetic resonance images, while only subtle changes were seen on survey radiographs. Post mortem investigation revealed a large heart base chemodectoma with multiple smaller tumours in the cranial mediastinum and a single tumour nodule on the thoracic aorta. The 5th cervical vertebral body had necrotic, haemorrhagic and lytic changes. Histopathology of the heart base tumour, the nodules in the cranial mediastinum and on the thoracic aorta and samples from the 5th cervical vertebra confirmed the presence of a malignant aortic or carotid body tumour originating from the chemoreceptor organs. Diagnostic imaging features and post mortem findings are described. To our knowledge, this is the first report of the magnetic resonance features of a metastatic chemodectoma in a dog.

A descriptive review of cardiac tumours in dogs and cats

“…Advanced imaging modalities such as computed tomography (CT), positron emission tomography (PET) scans (Fig. ) and magnetic resonance imaging (MRI) are useful diagnostic tools for the detection of cardiac tumours . Pneumopericardiography, angiography and gated radionuclide imaging are also reported.…”

Cases with manifestation of chemodectoma diagnosed in dogs in Department of Internal Diseases with Horses, Dogs and Cats Clinic, Veterinary Medicine Faculty, University of Environmental and Life Sciences, Wroclaw, Poland

“…Occasionally, they infiltrate myocardium [2]. Chemodectoma may manifest traits of a malignant tumour or of a benign tumour [1,3]. It should be added that in most cases chemodectoma metastases are infrequently encountered [4].…”

“…Diagnosis and treatment of cardiac tumours continue to be difficult. The diagnosis takes advantage of the most modern imaging techniques, i.e., ultrasonography, radiography and magnetic resonance [3,9]. Their accurate diagnosis, however, apart from standard staining with hematoxylin and eosin requires application of immunohistochemistry with use of antibodies specific for chromogranin A, synaptophysin and neuron-specific enolase [1,10-13].…”