• horse;
  • squamous cell carcinoma;
  • surgery;
  • computed tomography;
  • CT;
  • sinoscopy;
  • sinusotomy


Intrasinus neoplasia remains a rare but difficult condition to diagnose and treat in the horse, comprising approximately 8–19% of sinonasal disorders. There are, however, only a few case series upon which to base an approach to diagnosis and management (Cotchin 1967, 1977; Madewell et al. 1976; Stunzi and Hauser 1976; Sundberg et al. 1977; Priester and McKay 1980; Boulton 1985; Hilbert et al. 1988; Dixon and Head 1999; Head and Dixon 1999; Tremaine and Dixon 2001a,b). Squamous cell carcinoma (SCC) is the most common neoplasm observed in the equine paranasal sinuses. Evidence from other species would indicate that early recognition of SCC is crucial to the success of treatment and the ideal treatment remains complete excision with margins. Sinus involvement generally precludes this and we must often settle for surgical debulking, with or without adjunctive radio- or chemotherapy. In horses, as in other species, early recognition is difficult because clinical signs are nonspecific. Treatment is, therefore, often not attempted due to the extensive nature of lesions at presentation and the limited surgical access.

The accompanying article by Kowalczyk et al. (2011) showed how 3-dimensional (3D) imaging can identify the hallmark changes associated with aggressive neoplasia in the equine sinuses (Kowalczyk et al. 2011). The value of computed tomography (CT) and magnetic resonance imaging (MRI) lies in noninvasive early diagnosis as well as lesion monitoring post intervention. Where CT can be performed with the horse in the standing position, avoidance of general anaesthesia offers further value, especially as standing surgical techniques now allow thorough, minimally invasive evaluation and biopsy of the equine sinuses. In combination, standing CT and minimally invasive sinus surgery allow accurate and early diagnosis and monitoring of disease progression, opening the door for advances in surgical and adjunctive treatments for this complex condition.