Multiple Osseous Metastases of a Carotid Body Tumor in a Dog

Metastasis of malignant carotid body tumor to multiple bones was detected in a 13-year-old female Siberian husky dog. Radiographs exhibited an abnormal mass in the retropharyngeal site and osteolytic lesions in the vertebral bodies, spinous process, tibia, and ribs. At necropsy, multiple masses were observed in the bones as well as at the dorsal area of the retropharynx. Histologically, the tumor cells, arranged in sheets and clusters, had eosinophilic finely granular cytoplasm. Immunohistochemistry showed the tumor cells were positive for neuron-specific enolase and synaptophysin. Electron microscopy demonstrated a number of dense membrane-bound granules in the cytoplasm of the tumor cells. Based on these findings, this case was diagnosed as multiple bone metastases of a malignant carotid body tumor. Spinal cord damage induced by the tumor mass was the cause of the hind limb paralysis of the present dog.

Immunohistochemical characteristics of canine aortic and carotid body tumours

In an immunohistochemical study of 25 canine chemodectomas, 17 tumours were stained with antisera to neurone specific enolase and the same number were stained for synaptophysin; a single tumour was stained for S100. Staining for Ki-67 occurred in 18 cases; the Ki-67-labelling index and the intensity of immunostaining was increased in more pleomorphic and malignant tumours, as assessed on histological grounds. Immunohistochemistry did not aid in recognition of less well-differentiated tumours.

Metastatic intracavitary cardiac aortic body tumor in a dog

A mobile right-ventricular mass dynamically occluding the right ostium atrioventriculare in the systolic phase was detected in a 3-year-old male Tosa dog by echocardiography. At necropsy, multiple tumor masses of various sizes were observed in the heart base right ventricular lumen, myocardium, lung and liver. Dysplasia of tricuspid valve characterized by irregular shape of leaflets, upward malposition of large papillary muscles, and shortened and stout chordae tendineae was also detected. Histopathologically, the tumor cells, arranged in sheets or nests, were polyhedral with lightly eosinophilic and finely granular cytoplasm, and contained a hyperchromatic round or oval nucleus. By Grimelius' silver stain, tumor cells had cytoplasmic positive granules. Ultrastructurally, tumor cells contained characteristic small membrane-limited granules. This is the first report of metastatic intracavitary cardiac aortic body tumor in a dog.

Carotid body tumors in the dog. Eleven cases (1978-1988)

Case records of 11 dogs with histologically confirmed carotid body tumors were reviewed. Surgical excision had been attempted in ten dogs with carotid body tumors, and one dog had been euthanatized at diagnosis. There were no intraoperative deaths but perioperative mortality was 40%. Horner's syndrome and laryngeal paralysis were the most common postoperative morbidities. The median survival time after surgery alone in the four dogs that survived the perioperative period was 25.5 months (range, 12-45 months). Two dogs treated with postoperative radiation therapy had survival times of 6 and 27 months. Of the six dogs surviving the perioperative period, two dogs are still alive at 19 and 32 months postoperatively. Of the four dogs that died, one was euthanatized 12 months postoperatively for nontumor-related causes. The remaining three dogs died of distant metastases. The carotid body tumors studied were characterized by local tissue invasion, neurovascular complications after therapy, and a propensity to metastasize to multiple sites in the body.

Carotid body tumor: an incidental finding in older ranch mink

Carotid body tumors were found incidentally at necropsy in 15 ranch mink (Mustela vision), mostly royal pastels, kept for studies on slow viral diseases. The mink, five males and ten females, were 77 to 135 months old (mean age 107 months). Loosely or firmly attached at the bifurcation of the common carotid artery, and 11 larger tumors were smooth-surfaced, discrete, pale brown, globoid masses that varied from 2.5 to 16 mm in diameter. Four tumors of microscopic size occurred in otherwise normal-looking carotid bodies. All were composed of densely packed polygonal cells disposed in sheets and cords or arranged in clusters by a reticulin meshwork rich in blood vessels. Always unilateral, the tumors had not invaded locally or metastasized. As seen in the smallest tumors, the neoplastic cells usually arose centrally in the carotid body and formed an expansive growth that replaced much of the normal parenchyma without necessarily enlarging the organ beyond normal limits. The cause of the tumors was not apparent. All tumor-bearing mink had lived at an elevation of 1,100 meters, and none had suffered from any obvious chronic cardiopulmonary disease.

[Malignant chemodectoma of the carotid body in a basset hound bitch]

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Electromyography in the localization of spinal cord and nerve root neoplasia in dogs and cats

In 8 cases (6 dogs and 2 cats) of spinal cord and nerve root neoplasia, electromyography was used to localize the area of involvement. The locations of the lesions were confirmed at necropsy.

Carotid body tumors in the dog: a review and report of four cases

Of 3,837 canine neoplasms from case records at Kansas State University, only 4 were of carotid body tumors. Information on these 4 cases, added to that on 18 cases already reported, indicated that such tumors are found most frequently in old dogs, principally in brachycephalic breeds. Although predisposition toward the male sex has been suggested for tumors of the chemoreceptor system, none was observed for carotid body tumors. Multicentricity apparently is not uncommon for chemoreceptor tumors; 9 of the 22 dogs simultaneously had aortic body tumor.

Ultrastructure of canine carotid body and aortic body tumors. Comparison with tissues of thyroid and parathyroid origin

The microscopic structure of canine carotid and aortic body neoplasms was compared with that of other lesions of the neck and thorax. Carotid and aortic body adenomas consisted of clusters of large, polyhedral cells whose cytoplasm was filled with dense, membrane-bound granules and which lacked the normal relationship to sustentacular, nerve, and vascular cells. Unlike an ectopic thyroid adenoma, they had no thyroid follicles, PAS-stained cytoplasmic granules, acidic mucopolysaccharide foci, or dense tubules within the cisternae of the endoplasmic reticulum. Cells of the aortic body carcinoma were less differentiated than those of the adenoma. They contained fewer dense granules but had greater numbers of microfibrils and Golgi vesicles. Degeneration and necrosis of neoplastic tissue exaggerated differences from the adenomas. Cells from the metastatic tumor (pleural carcinomatosis) did not differ significantly from those of the primary tumor. Cells from thyroid and parathyroid lesions were significantly different ultrastructurally from those of carotid and aortic body tumors. Cells of the ectopic thyroid adenoma and thyroid carcinoma resembled normal follicular cells but were larger and contained characteristic PAS-stained granules and arrays of intracisternal microtubules. The parathyroid adenoma cells had few organelles; the dominant cytoplasmic structures were aggregates of membranes and residual bodies filled with lipofuscin.

Aortic body tumor in a cat. A case report

Multicentric, moderately malignant tumors of the nonchromaffin paraganglia at the site of the aortic body, at other sites of the cardiovascular system, and in the cranial mediastinal lymph nodes were discovered incidentally at autopsy of a 7-year-old female Siamese cat. Metastases were evident grossly in the myocardium, pericardium, and cranial mediastinal lymph nodes, and histologically as tumor emboli in the stromal vessels and in epicardial, myocardial, and pulmonary lymph channels.

Carotid body tumor in a cow

A carotid body tumor was found closely attached to the left carotid artery of a cow. The neoplastic tissue was well defined, and no metastases were observed, but there was a slight invasion of the capsule. Histologically, there was great resemblance to the corresponding tumor in dogs: pleomorphic cells, numerous vessels, peritheliomatous patterns, i.e. predominantly epithelial cells lined by endothelium, and pseudoalveoli enclosed by reticulum.