Abstract
Multilobular Bone Tumor (MBT) is a rare, slow-growing, and locally invasive neoplasm in middle-aged to older dogs, occurring predominantly in flat bones of the skull, pelvis, or ribs. This work reports the case of a 10-year-old, castrated, male Schnauzer, presenting with a tumorous growth in the incisor region measuring 1.0 x 0.7 x 0.6 centimeters for 30 days. Excisional biopsy revealed polygonal, hyperchromatic mesenchymal cells with oval nuclei and condensed chromatin, confirming a well-differentiated MLTB. However, the tumor recurred within 5 months, measuring 3.3 x 2.4 centimeters in the same region. Computed tomography (CT) revealed a mixed bone reaction, predominantly lytic, involving the incisive bone at the level of the incisor and canine teeth. The owner declined rostral maxillectomy and opted for a palliative approach with electrochemotherapy (bleomycin 15,000 UI/m2) at the tumor site. Complete remission was achieved within 28 days with macroscopic areas suggestive of scarring. The disease-free interval was 365 days without adjuvant therapy. However, at 435 days post-procedure (D0), recurrence was observed in the incisor region, accompanied by respiratory distress. Staging revealed pulmonary metastasis, leading to a decision for humane euthanasia owing to poor prognosis. Electrochemotherapy for oral MLTB in this dog demonstrated good efficacy, prolonged local control, and no regional functional impairments.
References
Banks, T. A., & Straw, R. C. (2004). Multilobular osteochondrosarcoma of the hard palate in a dog. Australian Veterinary Journal, 82(7), 409-412. https://doi.org/10.1111/j.1751-0813.2004.tb11127.x. PMid:15354847.
Vedrine, B. (2023). Multilobular osteochondroma of the vertical ramus of the mandible in a cat. Topics in Companion Animal Medicine, 53-54, 100776. https://doi.org/10.1016/j.tcam.2023.100776.
Cook, S., Civello, A., Lam, R., Fenn, J., Neilson, D., Priestnall, S., & Decker, S. (2017). Rapid postoperative recurrence of a cranial multilobular tumor of bone in a young dog. Clinical Case Reports, 5(12), 1995-1999. https://doi.org/10.1002/ccr3.1243. PMid:29225843.
Cray, M., Selmic, L. E., Kindra, C., Abrams, B., Story, A., Hovis, K., Wustefeld-Janssens, B., Park, K., Grimes, J. A., Oblak, M., Chen, C., Casale, S., Rollins, A., Kennedy, K., Wilson, J., Culp, W. T. N., & Wavreille, V. A. (2021). Analysis of the risk factors associated with complications following mandibulectomy and maxillectomy in dogs. Journal of the American Veterinary Medical Association, 259(3), 265-274. https://doi.org/10.2460/javma.259.3.265. PMid:34242072.
Dernell, W. S., Straw, R. C., Cooper, M. F., Powers, B. E., LaRue, S. M., & Withrow, S. J. (1998). Multilobular osteochondrosarcoma in 39 dogs: 1979-1993. Journal of the American Animal Hospital Association, 34(1), 11-18. https://doi.org/10.5326/15473317- 34-1-11. PMid:9527424.
Fontes, G. S., Cook, M. R., Lumbrezer-Johnson, S., Hostnik, E. T., Lapsley, J. M., Tremolada, G., Pool, R. R., & Selmic, L. E. (2023). Multilobular tumor of bone arising from the palatomaxillary suture line in the skull of a dog. The Canadian Veterinary Journal = La Revue Vétérinaire Canadienne, 64(6), 545-548. PMid:37265818.
Hathcock, J. T., & Newton, J. C. (2000). Computed tomographic characteristics of multilobular tumor of bone involving the cranium in 7 dogs and zygomatic arch in 2 dogs. Veterinary Radiology & Ultrasound : The Official Journal of the American College of Veterinary Radiology and the International Veterinary Radiology Association, 41(2), 214-217.
Lee, S. H., Kim, D. H., Bae, K., Jeong, S. W., Yoon, K. A., Yoon, H. Y., Do, S. H., Kim, B., & Kim, J. H. (2022). Adjuvant therapy with imatinib for an incompletely resected multilobular tumour of bone in a dog. Veterinární Medicína, 67(11), 590-597. https://doi.org/10.17221/85/2021-VETMED. PMid:38846793.
Leonardi, L., Carrano, A., & Floris, L. (2014). Multilobular tumor of the zygomatic bone in a dog. Open Veterinary Journal, 4(2), 9-11. https://doi.org/10.5455/OVJ.2014.v4.i1.p9. PMid:26623332.
Marangon, W. F., Melo, J. B., Rodrigues, N. S., Merlini, N. B., Assis, M. M. Q., & Assis, M. M. Q. (2020). Multilobular osseous tumor in a dog: Case report. Brazilian Journal of Development, 6(10), 83069-83076. https://doi.org/10.34117/ bjdv6n10-659.
Moretti, G., Dentini, A., Beccati, F., Arcelli, R., Matteo, I. D., Giovannini, G., & Bufalari, A. (2022). Palliative repeated electroporations of oral tumours in dogs: A case series. Frontiers in Veterinary Science, 9, 1004811. https://doi.org/10.3389/fvets.2022.1004811. PMid:36439338.
Murphy, B. G., Bell, C. M., & Soukup, J. W. (2020). Veterinary oral and maxillofacial pathology. John Wiley & Sons.
Nemec, A., Milevoj, N., Lampreht Tratar, U., Serša, G., Čemažar, M., & Tozon, N. (2020). Electroporation-based treatments in small animal veterinary oral and maxillofacial oncology. Frontiers in Veterinary Science, 7, 575911. https://doi.org/10.3389/fvets.2020.575911. PMid:33134356.
Nguyen, S. M., Thamm, D. H., Vail, D. M., & London, C. A. (2015). Response evaluation criteria for solid tumours in dogs (v1.0): A Veterinary Cooperative Oncology Group (VCOG) consensus document. Veterinary and Comparative Oncology, 13(3), 176-183. https://doi.org/10.1111/vco.12032. PMid:23534501.
Psychas, V., Loukopoulos, P., Polizopoulou, Z. S., & Sofianidis, G. (2009). Multilobular tumour of the caudal cranium causing severe cerebral and cerebellar compression in a dog. Journal of Veterinary Science, 10(1), 81-83. https://doi.org/10.4142/jvs.2009.10.1.81. PMid:19255529.
Sritrakoon, N., Wibulchan, W., Karntip, W., Sirinarumitr, T., & Thayananuphat, A. (2023). Radiotherapy in combination with exenteration and partial orbitectomy for orbital multilobular tumor of bone in a Cocker Spaniel. Open Veterinary Journal, 13(11), 1485-1490. https://doi.org/10.5455/OVJ.2023.v13.i11.13. PMid:38107220.
Taques, M. M., Guedert, R., Moreno, K., Monte Mor Rangel, M., & Suzuki, D. O. H. (2021). Adjuvant electrochemotherapy after debulking in canine bone osteosarcoma infiltration. Artificial Organs, 45(3), 309-315. https://doi.org/10.1111/ aor.13820. PMid:32959401.
Tellado, M., Mir, L. M., & Maglietti, F. (2022). Veterinary guidelines for electrochemotherapy of superficial tumors. Frontiers in Veterinary Science, 9, 868989. https://doi.org/10.3389/fvets.2022.868989. PMid:35968026.
Tipirneni, Y., Soltero-Rivera, M., Blandino, A., & Goldschmidt, S. (2024). Understanding canine oral neoplasia: Intrinsic rather than extrinsic features represent key factors in a 39-year analysis. Journal of the American Veterinary Medical Association, 263(3), 368-376. https://doi.org/10.2460/javma.24.09.0594. PMid:39642465.
Tozon, N., Lampreht Tratar, U., Znidar, K., Sersa, G., Teissie, J., & Cemazar, M. (2016). Operating procedures of the electrochemotherapy for treatment of tumor in dogs and cats. Journal of Visualized Experiments, 116(116), e54760. https://doi.org/10.3791/54760. PMid:27805594.
Thompson, K. G., & Dittmer, K. G. (2017). Tumors of bone. In D. J. Meuten (Ed.), Tumors in domestic animals (5th ed., pp. 356-424). Wiley-Blackwell

This work is licensed under a Creative Commons Attribution 4.0 International License.
Copyright (c) 2026 Priscila Oliveira Martins, Guilherme Freitas de Souza, André Gustavo Alves Holanda, Denner Santos dos Anjos

