RAPPORT DE CAS
CASE REPORT
Nasal chondrosarcoma in a Simmental cow E. Beytut, E. Kilic, S. Ozturk, B. Ozba Abstract — The pathologic features of a nasal chondrosarcoma, a rare tumor of bovines, in a Simmental cow are described. Upon clinical examination, stertor, difficulty in breathing, poor body condition, and a nasal mass were found. Histopathologic examination revealed that the mass was composed mostly of numerous cartilaginous lobules surrounded by spindle-shaped cells, often showing mitotic figures, atypical chondrocytes, and lacunae containing 2 or more cells. On the basis of the histological features, the mass was diagnosed as a nasal chondrosarcoma. Résumé — Chondrosarcome nasal chez une vache Simmental. Les caractéristiques pathologiques des chondrosarcomes nasaux, tumeurs rencontrées rarement chez les bovins, ont été décrites chez une vache Simmental. L’examen clinique a révélé une respiration stertoreuse et laborieuse, une mauvaise condition physique et une masse nasale. L’examen histopathologique a révélé une masse composée majoritairement de nombreux lobules cartilagineux entourés de cellules fusiformes présentant fréquemment des figures mitotiques, des chondrocytes atypiques et des lacunes contenant 2 cellules ou plus. Sur la base des caractéristiques histologiques, un diagnostic de chondrosarcome nasal a été posé. (Traduit par Docteur André Blouin) Can Vet J 2006;47:349–351
hondrosarcoma is a malignant neoplasm, characterC ized by the formation of cartilage, but not bone (1,2). In abattoir surveys, the frequency of malignant or benign cartilaginous neoplasms in cattle has been found to be less than 1% of all neoplasms (3,4). However, cartilaginous neoplasms are the 2nd most common sarcoma affecting bones in domestic animals, except for sheep, and occur commonly in adult dogs of large breeds (5). Flat bones are involved more often than long bones. Most of the few chondrosarcomas reported in cattle and horses were also located in flat bones (5). The nasal cavity is more commonly affected by chondrosarcoma in dogs (34% of cases) (5,6). However, in cattle, extraskeletal location of the neoplasm has rarely been reported (2,3). This report describes the pathologic features of a chondrosarcoma located in the nasal cavity of an adult Simmental cow, as this neoplasm is rarely encountered in cattle and has never been reported in this location in this species.
Case description A 5-year-old Simmental cow was admitted to the Department of Veterinary Surgery, University of Kafkas, for clinical examination on April 25, 2002. Stertor, intermittent dry coughing, difficulty in breathing, and chronic weight loss had occurred over the preceding year. On Department of Pathology (Beytut); Department of Surgery (Kilic, Ozturk, Ozba), Faculty of Veterinary Medicine, University of Kafkas, Kars, Turkey. Address all correspondence and reprint requests to Dr. Enver Beytut; e-mail:
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A
B
Figure 1. A. Tumor mass following surgical removal. B. Cut surface of the mass is milky-white in appearance, with hemorrhages.
clinical examination, the cow was in poor bodily condition, with a rough hair coat. The rectal temperature was 39°C; the heart rate, 95 beats/min; and the respiratory rate, 60 breaths/min. Upon auscultation of the lungs, the sounds were clear and slightly increased. A mass was clearly seen in the left nasal cavity. The nasal cavity was surgically opened in a routine operation, and the firm mass was completely occluding the nasal cavity. A purulent exudate multifocally covered the mass, especially near the turbinates. The dimensions of the mass were approximately 15 5 4 cm (Figure 1A). The mass was surgically removed and submitted to the Department of Veterinary Pathology for histopathological evaluation. 349
Figure 2. A cartilaginous lobule showing atypical chondrocytes surrounded by a spindle cell margin. Hematoxylin and eosin (H&E), Bar = 166 m
Figure 4. A mitotic figure (arrowhead) in the telophase stage in the spindle cell tumor margin. Hematoxylin and eosin (H&E), Bar = 11 m
Hyperchromatic cells and mitoses were clearly observed in those areas (Figure 4). When sections were stained with PAS, the spindle-cell areas did not stain, but the cytoplasm of the neoplastic chondrocytes was PAS-positive, with purplish staining of the cytoplasmic granules. With Mallory’s triple stain, the extralobular matrix stained light blue, the chondrocytes, brownish, and the spindle cells, pinkish.
Discussion
Figure 3. Lacunae commonly containing 2 cells (arrowheads). Hematoxylin and eosin (H&E), Bar = 11 m
On cross-section, the mass was composed of small lobules of milky-white, soft to moderately firm tissue, with a slimy consistency, widespread hemorrhages, and a purulent fistule in the center of the tumor (Figure 1B). Tissue samples taken from the tumor were fixed in 10% buffered formalin, processed routinely for sectioning, and then stained with hematoxylin and eosin (H&E). Some sections were also stained with Crossman’s modification of Mallory’s triple stain (7) and periodic acidschiff (PAS). Microscopic examination revealed that the tumor was composed of numerous cartilaginous lobules surrounded by spindle-shaped cells (Figure 2). A lumen, resembling a vessel, occluded by an amorphous material, compatible with chondroid matrix, was usually seen within the center of each lobule. Similar spaces, lined by endothelial cells and containing blood cells, were also seen clearly within the spindle-cell regions. In some lobules, extracellular chondroid matrix was abundant and chondrocytes of various sizes and shapes were irregularly dispersed within the matrix. Binucleated and atypical chondrocytes with a spindle-shaped appearance were commonly seen in the lobular structures. The lacunae often contained 2 or more cells, some of which had large nuclei and prominent nucleoli (Figure 3). Mitotic figures and hyperchromatic cells were often detected in the cartilaginous lobules. Spindle-shaped cells surrounding the cartilaginous lobules was a common feature in all the sections. 350
Chondrosarcomas are rarely encountered tumors in bovine species (5), in contrast to humans, in whom this neoplasm is the third most frequent malignant tumor of bones (8). Although this cartilaginous neoplasm has been reported particularly in the skeletal system, commonly in flat bones (8–10), the nasal region is the second most common site in dogs (1,5,6). However, in cattle, this tumor has not been reported in the nasal cavity. Since most bovine tumors are encountered incidentally in abattoirs, the clinical symptoms caused by neoplasms are not well documented. Nevertheless, tumors located in the nasal cavity have been reported to cause stertor, purulent to bloody discharges, and nasal obstruction, when the tumor mass fills the cavity (5), as in this case. Chondrosarcomas form large and firm masses when allowed to pursue a full clinical course without surgical intervention, and the cut surface of such masses resembles hyaline cartilage, with a milky or bluish-white appearance, chalky areas of mineralization or ossification, and a slimy consistency, which is particularly characteristic of nasal chondrosarcomas (1,5,8,9). Similarly, in the present case, the cut surface of the tumor mass was milky white, slimy, and hemorrhagic. A histological diagnosis of chondrosarcoma is not always possible, since many well-differentiated tumors are erroneously diagnosed as benign cartilaginous neoplasms. The histologic appearance of a chondrosarcoma may vary, depending on the grade of the neoplasm; the presence of mitoses and abnormal chondrocytes with plump, atypical, hyperchromatic nuclei has to be observed for a definitive diagnosis (5,8). It has been suggested that the majority of tumors of cartilage grow primarily by matrix synthesis rather than by rapid cell proliferation and this may explain why Can Vet J Volume 47, April 2006
chondrosarcomas expand more slowly than other tumors, like osteosarcomas (9). Cell proliferation in chondrosarcomas may be so slow that the only morphological indication of cell division is the presence of binucleated cells or lacunae containing more than 1 chondrocyte (2,5,9), as found in this case. Also, the lumen found within the center of the cartilaginous lobules was most likely formed by primitive vessels, when spindle cells transformed into chondroblasts. The spindle cell tumor margin is a fairly common feature of animal chondrosarcomas, especially tumors of the nasal cavity (5,6). In the present case, a spindle cell tumor region and, in some areas, its differentiation to chondroblasts was commonly noticed at the periphery of the cartilaginous lobules. Such poorly differentiated spindle cells at the periphery of well-differentiated chondrosarcomas, which is called dedifferentiation of the tumor, is reported to worsen the prognosis of such tumors in humans (5). It is documented that chondrosarcomas involving the nasal cavity have a tendency to metastasize late in the course of the disease and that recurrence following surgical removal sometimes occurs (1). Also, Hahn et al (6) reported that the metastatic rate for nasal chondrosarcomas was lower than 15%. Of the 27 necropsies reported in dogs with a diagnosis of nasal chondrosarcoma, 4 cases had metastasized to the lungs. In this case, about 6 mo after surgery, the owner of the cow confirmed that the animal was alive and that there had been no visible recurrence in the nasal cavity. However, 15 mo after surgical removal of the tumor, the animal began to experience severe difficulty in breathing; this clinical problem might indicate a recurrence or metastasis of the tumor. Unfortunately, the animal could not be reexamined. In conclusion, even though distinguishing a chondrosarcoma from a benign tumor of cartilage is difficult, the gross and histopathological findings detected in this case were consistent with a diagnosis of nasal CVJ chondrosarcoma.
5. Thompson KG, Pool RR. Tumors of bones. In: Meuten DJ, ed. Tumors in Domestic Animals. 4th ed. Ames: Iowa State Univ Press, 2002:245–317. 6. Hahn KA, McGavin MD, Adams WH. Bilateral renal metastases of nasal chondrosarcoma in a dog. Vet Pathol 1997;34:352–355. 7. Crossman GA. Modification of Mallory’s connective tissue stain with a discussion of the principles involved. Anat Rec 1937;69: 33–38. 8. Unni KK, Inwards CY. Tumors of the osteoarticular system. In: Fletcher CDM, ed. Diagnostic Histopathology of Tumors. 2nd ed. Vol 2. London: Churchill Livingstone, 2000:1541–1607. 9. Buckwalter JA. The structure of human chondrosarcoma proteoglycans. J Bone Joint Surg 1983;65:958–974. 10. Yildiz F, Gurel A, Yesildere T, Ozer K. Frontal chondrosarcoma in a cat. J Vet Sci 2003;4:193–194.
References 1. Palmer N. Bones and Joints. In: Jubb KVF, Kennedy PC, Palmer N, eds. Pathology of Domestic Animals. 4th ed. Vol 1. New York: Academic Pr, 1993:1–181. 2. Uno K, Kataoka H, Kadota K. Extraskeletal mesenchymal chondrosarcoma in a cow. J Comp Pathol 1989;101:31–38. 3. Richardson DW, Acland HM. Chondrosarcoma in a cow. Cornell Vet 1983;73:137–143. 4. Acland HM. Chondrosarcoma in a cow. J Comp Pathol 1983;93: 585–589.
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