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Computed Tomographic and Magnetic Resonance Imaging Features of Oral Melanoma in a Dog

  • Arim Lee (College of Veterinary Medicine, Research Institute of Veterinary Medicine, Chungnam National University) ;
  • Seokmin Lee (College of Veterinary Medicine, Research Institute of Veterinary Medicine, Chungnam National University) ;
  • Hojung Choi (College of Veterinary Medicine, Research Institute of Veterinary Medicine, Chungnam National University) ;
  • Youngwon Lee (College of Veterinary Medicine, Research Institute of Veterinary Medicine, Chungnam National University)
  • Received : 2023.09.06
  • Accepted : 2023.09.30
  • Published : 2023.10.31

Abstract

Oral melanoma is the most common type of oral tumor in dogs. In this report, computed tomography (CT) and magnetic resonance imaging (MRI) were performed to diagnose a right oral pigmented mass in an 8-year-old dog. The oral mass appeared as a homogeneous soft tissue density parenchyma on pre-contrast CT images, and with heterogeneous enhancement on post-contrast images. Bone destruction of the right mandibular body around the mass and mild enlargement of the right mandibular lymph node were also found. On MRI, the bulky oral mass showed mixed hyperintensity and isointensity compared to the adjacent muscle, where irregular hyperintensity on T1-weighted images corresponded to hypointensity on the T2-weighted images. Based on the physical examinations and imaging results, melanoma was suspected and confirmed via fine-needle aspiration. These unique MRI signals were due to the high paramagnetic melanin content in the tumor, therefore MRI examination could be useful for diagnosis of melanoma.

Keywords

References

  1. Bergman PJ. Canine oral melanoma. Clin Tech Small Anim Pract 2007; 22: 55-60.  https://doi.org/10.1053/j.ctsap.2007.03.004
  2. Choisunirachon N, Lin LS, Tanaka Y, Saeki K, Fujiwara R, Nishimura R, et al. Retrospective study of computed tomographic characterization of canine oral malignant melanoma in 24 dogs. Thai J Vet Med 2014; 44: 497-503.  https://doi.org/10.56808/2985-1130.2601
  3. Felix CC, Hyde JS, Sarna T, Sealy RC. Interactions of melanin with metal ions. Electron spin resonance evidence for chelate complexes of metal ions with free radicals. J Am Chem Soc 1978; 100: 3922-3926.  https://doi.org/10.1021/ja00480a044
  4. Gunbey HP, Gunbey E, Sayit AT, Aslan K. Magnetic resonance imaging (MRI) appearances of primary amelanotic malign melanoma in the nasal cavity: a rare case. J Clin Diagn Res 2015; 9: TD01-TD03.  https://doi.org/10.7860/JCDR/2015/11276.5546
  5. Hayashi T, Ito J, Katsura K, Honma K, Shingaki S, Ikarashi T, et al. Malignant melanoma of mandibular gingiva; the usefulness of fat-saturated MRI. Dentomaxillofac Radiol 2002; 31: 151-153.  https://doi.org/10.1038/sj.dmfr.4600679
  6. Houghton AN, Polsky D. Focus on melanoma. Cancer Cell 2002; 2: 275-278.  https://doi.org/10.1016/S1535-6108(02)00161-7
  7. Kafka UC, Carstens A, Steenkamp G, Symington H. Diagnostic value of magnetic resonance imaging and computed tomography for oral masses in dogs. J S Afr Vet Assoc 2004; 75: 163-168.  https://doi.org/10.4102/jsava.v75i4.476
  8. Lee PH, Wang LC, Lee EJ. Primary intracranial melanoma. J Cancer Res Pract 2017; 4: 23-26.  https://doi.org/10.1016/j.jcrpr.2016.09.001
  9. Lee S, Jang Y, Lee G, Jeon S, Kim D, Choi J. CT features of malignant and benign oral tumors in 28 dogs. Vet Radiol Ultrasound 2021; 62: 549-556.  https://doi.org/10.1111/vru.12996
  10. Liptak JM, Withrow SJ, Selting KA, Turek MM. Cancer of the gastrointestinal tract. In: Withrow SJ, Vail DM, Page RL, editors. Withrow and MacEwen's small animal clinical oncology. 5th ed. St. Louis: Elsevier/Saunders. 2013: 381-395. 
  11. Marx HF, Colletti PM, Raval JK, Boswell WD Jr, Zee CS. Magnetic resonance imaging features in melanoma. Magn Reson Imaging 1990; 8: 223-229.  https://doi.org/10.1016/0730-725X(90)90093-H
  12. McEntee MC. Clinical behavior of nonodontogenic tumors. In: Verstraete FJM, Lommer MJ, editors. Oral and maxillofacial surgery in dogs and cats. Philadelphia: Saunders. 2012: 387-402. 
  13. Nishiya AT, Massoco CO, Felizzola CR, Perlmann E, Batschinski K, Tedardi MV, et al. Comparative aspects of canine melanoma. Vet Sci 2016; 3: 7. 
  14. Patnaik AK, Mooney S. Feline melanoma: a comparative study of ocular, oral, and dermal neoplasms. Vet Pathol 1988; 25: 105-112.  https://doi.org/10.1177/030098588802500201
  15. Ramos-Vara JA, Beissenherz ME, Miller MA, Johnson GC, Pace LW, Fard A, et al. Retrospective study of 338 canine oral melanomas with clinical, histologic, and immunohistochemical review of 129 cases. Vet Pathol 2000; 37: 597-608.  https://doi.org/10.1354/vp.37-6-597
  16. Smith SH, Goldschmidt MH, McManus PM. A comparative review of melanocytic neoplasms. Vet Pathol 2002; 39: 651-678.  https://doi.org/10.1354/vp.39-6-651
  17. Todoroff RJ, Brodey RS. Oral and pharyngeal neoplasia in the dog: a retrospective survey of 361 cases. J Am Vet Med Assoc 1979; 175: 567-571. 
  18. Uchiyama Y, Murakami S, Kawai T, Ishida T, Fuchihata H. Primary malignant melanoma in the oral mucosal membrane with metastasis in the cervical lymph node: MR appearance. AJNR Am J Neuroradiol 1998; 19: 954-955. 
  19. Williams LE, Packer RA. Association between lymph node size and metastasis in dogs with oral malignant melanoma: 100 cases (1987-2001). J Am Vet Med Assoc 2003; 222: 1234-1236.  https://doi.org/10.2460/javma.2003.222.1234
  20. Wu CC, Huang WH, Liao PW, Chang YP. Diagnosis of meningeal melanomatosis in a dog using magnetic resonance imaging and cerebrospinal fluid findings. J Vet Med Sci 2021; 83: 94-99.  https://doi.org/10.1292/jvms.20-0556
  21. Yoon H, Yu J, An T, Lee H, Kim H, Kim D, et al. Magnetic resonance findings of a canine benign uveal melanocytoma. J Vet Clin 2018; 35: 233-236. https://doi.org/10.17555/jvc.2018.10.35.5.233