Primary omentum extraskeletal osteosarcoma in a dog: case report


ultrasound, extraskeletal osteosarcoma, dog.

How to Cite

Soares, C. T. E., Medeiros, F. P., & Martins Junior, R. (2023). Primary omentum extraskeletal osteosarcoma in a dog: case report. Brazilian Journal of Veterinary Medicine, 45, e000423.


A rescued male mixed-breed dog, approximately nine years old, was evaluated due to progressive weight loss and an enlarged abdomen. An ultrasound revealed a large, indeterminate mass with mineral-like margins visible on the radiographs. The animal underwent an exploratory laparotomy, and the mass was excised. Histopathological analysis revealed characteristics consistent with a primary omentum extraskeletal osteosarcoma. This rare neoplasm, originating from mesenchymal cell proliferation and bone matrix production, is highly malignant. It often results in death due to metastasis and local recurrence or necessitates euthanasia post-diagnosis in certain cases.


Duffy, D., Selmic, L. E., Kendall, A. R., & Powers, B. E. (2017). Outcome following treatment of soft tissue and visceral extraskeletal osteosarcoma in 33 dogs: 2008-2013. Veterinary and Comparative Oncology, 15(1), 46-54. PMid:25643914.

Gârjoabă, I., Tudor, N., Soare, T., Tănase, A., & Vlăgioiu, C. (2009). Extraskeletal osteosarcoma in dogs: Presentation of two cases. Lucrări Ştiinłifice Medicină Veterinară, 42, 107-110.

Guim, T. N., Cecco, B. S., Laisse, C. J. M., Schmitt, B., Henker, L. C., Vieira, C. D., Driemeier, D., Pavarini, S. P., & Sonne, L. (2019). Epidemiological and pathologic aspects of extra-skeletal osteosarcoma in dogs. Semina: Ciências Agrárias, 40(6, Suppl. 2), 3089-3098.

Kuntz, C. A., Dernell, W. S., Powers, B. E., & Withrow, S. (1998). Extraskeletal osteosarcomas in dogs: 14 cases. Journal of the American Animal Hospital Association, 34(1), 26-30. PMid:9527426.

Langenbach, A., Anderson, M. A., Dambach, D. M., Sorenmo, K. U., & Shofer, F. D. (1998). Extraskeletal osteosarcomas in dogs: A retrospective study of 169 cases (1986-1996). Journal of the American Animal Hospital Association, 34(2), 113-120. PMid:9507423.

Leonardi, L. (2022). Tumors of the musculoskeletal system. In L. Leonardi (Ed.), Bone tumors in domestic animals: Comparative clinical pathology (p. 73). Switzerland: Springer Nature.

MacKenzie, S., Hecht, S., Sura, P. A., & Craig, L. E. (2012). What is your diagnosis? Journal of the American Veterinary Medical Association, 240(7), 817-818. PMid:22443433.

Patnaik, A. K. (1990). Canine extraskeletal osteosarcoma and chondrosarcoma: A clinicopathologic study of 14 cases. Veterinary Pathology, 27(1), 46-55. PMid:2309381. Piedra-Mora, C., Barrantes-Murillo, D., & Alfaro-Alarcón, A. (2016). Osteosarcoma extraesquelético retroperitoneal en un perro: Reporte de un caso. Ciencias Veterinarias (Heredia), 34(1), 55-63.

Creative Commons License

This work is licensed under a Creative Commons Attribution 4.0 International License.

Copyright (c) 2023 Caroline Tessmer Elias Soares, Fernanda Peres Medeiros, Raul Martins Junior