Head and neck squamous cell carcinoma with heterotopic ossification, lymphovascular invasion, and nodal and pulmonary metastases in a 23-year-old Morgan gelding.
Abstract: Primary squamous cell carcinoma of the head and neck occurs in the skin or squamous epithelial lining tissues of the oral cavity, pharynx, larynx, and sinonasal tract. Although it is a common tumor in horses, distant metastatic spread to the lung is rare. This report describes a case of metastatic pulmonary squamous cell carcinoma in a 23-year-old Morgan gelding. The clinical signs displayed by this gelding in some ways mimicked the typical presentation of equine multinodular pulmonary fibrosis or thoracic lymphoma. The postmortem diagnosis in this case was head and neck squamous cell carcinoma, but a primary site of origin could not be ascertained. Cancer-associated heterotopic ossification (HO) was also identified in this case; this is an exceedingly rare finding with equine pulmonary neoplasia. Key clinical message: Careful physical examination should be undertaken in all horses presenting with clinical signs of intrathoracic disease. Clinical and radiographic abnormalities in this case of pulmonary metastatic disease resembled some of those associated with interstitial pneumonia. Rarely encountered in domestic animal species, there has been only 1 previous report of HO in a case of oronasal carcinoma in a horse. Carcinome épidermoïde de la tête et du cou avec ossification hétérotopique, envahissement lymphovasculaire et métastases ganglionnaires et pulmonaires chez un hongre Morgan de 23 ans. Le carcinome épidermoïde primitif de la tête et du cou survient dans la peau ou les tissus épithéliaux squameux de la cavité buccale, du pharynx, du larynx et du tractus naso-sinusien. Bien qu’il s’agisse d’une tumeur courante chez les chevaux, la propagation métastatique à distance au poumon est rare. Ce rapport décrit un cas de carcinome épidermoïde pulmonaire métastatique chez un hongre Morgan de 23 ans. Les signes cliniques présentés par ce hongre imitaient à certains égards la présentation typique de la fibrose pulmonaire multinodulaire équine ou du lymphome thoracique. Le diagnostic post-mortem dans ce cas était un carcinome épidermoïde de la tête et du cou, mais un site d’origine primaire n’a pas pu être déterminé. L’ossification hétérotopique associée au cancer (HO) a également été identifiée dans ce cas; il s’agit d’une découverte extrêmement rare avec la néoplasie pulmonaire équine.Message clinique clé :Un examen physique attentif doit être entrepris chez tous les chevaux présentant des signes cliniques de maladie intrathoracique. Les anomalies cliniques et radiographiques dans ce cas de maladie pulmonaire métastatique ressemblaient à certaines de celles associées à la pneumonie interstitielle. Rarement rencontré chez les espèces animales domestiques, il n’y a eu qu’un seul signalement antérieur d’HO dans un cas de carcinome oronasal chez un cheval.(Traduit par Dr Serge Messier).
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The study reports a rare case of metastatic squamous cell carcinoma from the head and neck, spreading to the lung in a 23-year-old male horse [Morgan gelding]. An unusual symptom, heterotopic ossification (abnormal bone growth), was discovered, typically scarce in cases concerning equine pulmonary neoplasia.
Case Presentation
This instance describes the discovery and examination of metastatic pulmonary squamous cell carcinoma in a 23-year-old Morgan gelding.
The clinical signs imitated other known equine diseases such as multinodular pulmonary fibrosis and thoracic lymphoma, leading to potential medical misdirection.
The primary site of carcinoma origin could not be conclusively determined, despite postmortem diagnosis.
Significant Findings
A rare phenomenon known as cancer-associated heterotopic ossification (HO), which represents abnormal bone growth in non-skeletal tissues, was identified.
This abnormality is incredibly infrequent in connection with equine pulmonary neoplasia, making this case a significant observation.
Implications
These findings underscore the necessity for careful physical examination in horses, especially those presenting with clinical signs of diseases characteristically intrathoracic, as misleading symptoms can complicate an accurate prognosis.
The clinical and radiographic abnormalities shown during examination simulated interstitial pneumonia, which further compounds the complexities of diagnosis.
A rare occurrence primarily in domestic animals, only one previous account of HO tied to a case of oronasal carcinoma in a horse has been reported before this study.
Conclusion
Due to the rarity and comparatively cryptic nature of metastatic squamous cell carcinoma to the lung in horses, this report contributes to the limited body of knowledge regarding these types of equine diseases.
It emphasizes the importance of vigilant physical and radiographic examination procedures and the need for more research to identify the primary carcinoma origin in such cases.
Cite This Article
APA
Townsend KS, Johnson PJ, Kuroki K.
(2023).
Head and neck squamous cell carcinoma with heterotopic ossification, lymphovascular invasion, and nodal and pulmonary metastases in a 23-year-old Morgan gelding.
Can Vet J, 64(7), 627-632.
Veterinary Medicine and Surgery, University of Missouri, 900 East Campus Drive, Columbia, Missouri 65211, USA (Townsend, Johnson); Veterinary Pathobiology, University of Missouri, 1600 East Rollins, Columbia, Missouri 65211, USA (Kuroki).
Johnson, Philip J
Veterinary Medicine and Surgery, University of Missouri, 900 East Campus Drive, Columbia, Missouri 65211, USA (Townsend, Johnson); Veterinary Pathobiology, University of Missouri, 1600 East Rollins, Columbia, Missouri 65211, USA (Kuroki).
Kuroki, Keiichi
Veterinary Medicine and Surgery, University of Missouri, 900 East Campus Drive, Columbia, Missouri 65211, USA (Townsend, Johnson); Veterinary Pathobiology, University of Missouri, 1600 East Rollins, Columbia, Missouri 65211, USA (Kuroki).
MeSH Terms
Male
Animals
Horses
Squamous Cell Carcinoma of Head and Neck / veterinary
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