Three cases of osteoma and an osseous fibroma of the paranasal sinuses of horses in South Africa.

The study details four cases of horses in South Africa suffering from facial issues related to bone tumors in the paranasal sinuses. Of these, three were identified as osteomas, with the fourth being an ossifying fibroma.

Background and Case Presentation

• The article commences with reports of four South African horses brought to the Onderstepoort Veterinary Academic Hospital. The horses were experiencing facial asymmetry, nasal discharge, and hindrance in the flow of normal nasal passage airflow, all of which indicated possible issues with their maxillary sinuses.
• Radiographic examination was used to identify the root cause of these symptoms. In two of these cases, the results from the radiographic examination showed clear, unilateral, mineralised masses within the maxillary sinuses.
• The other two horses revealed less mineralisation. In order to investigate further, the researchers required access to the masses. This was achieved by the creation of frontonasal bone flaps or by trephination of the maxillary sinuses, both surgical interventions.

Diagnosis and Conclusion

• The histopathological examination of the masses confirmed the presence of osteomas in three horses. The fourth was diagnosed with an ossifying fibroma.
• However, the prognosis for the horses was not positive despite the intervention. Two of them were euthanasied after the surgical procedures due to low likelihood of recovery.
• The paper concludes by characterising the nature of the identified tumors. Osteomas are expansive tumors that shape themselves along the sinus’ complex communication, making surgical removal difficult. On the other hand, ossifying fibromas, though rare, present as large, solitary, expansive lesions found predominantly in horses. They are understood to have an unusual predilection for the horse’s rostral mandible.