Early diagnosis may hold the key to the successful treatment of nasal and paranasal sinus neoplasia in the horse

Abstract

Summary 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.

Maxillary odontogenic myxoma in young horses: Six cases (2003–2011)

“…However, it is still the authors' belief that the cases described in the current report suffered inoperable lesions upon presentation to the hospital. Early diagnosis and treatment has been advocated by others for successful treatment of sinonasal neoplasia in horses (Witte and Perkins ). The short duration of clinical signs and rapid expansion of the lesions in the cases presented here negated the possibility for treatment and prognosis for maxillary odontogenic myxoma is considered poor.…”

Equine sinonasal tumours: Does reporting of single cases and case series still advance the neglected field of equine clinical oncology?

“…), with the tumours obviously being present for an unknown duration prior to that. Therefore, although early diagnosis of sinonasal neoplasia is important if they are to be effectively treated (Witte and Perkins ), because of the unique anatomical site where these tumours develop, early diagnosis is usually impossible. In horses, the less common, benign fibro‐osseous sinonasal tumours that are well defined, allow complete surgical excision and can be effectively treated even when longstanding (Dixon and Head ).…”

“…Intralesional chemotherapy with agents such as cisplatin combined with surgical debulking is an alternative treatment (Theon et al . ; Witte and Perkins ) but evidence of efficacy of this multimodal therapy is currently lacking and such therapy in the ethmoid region risks causing barin damage (Maischberger et al . ).…”

“…Dixon and Head () found that just 20% of 28 horses with sinonasal neoplasia had metastases to drainage lymph nodes (although another 42% of affected horses had reactive lymphadenopathy of these lymph nodes) and no distant metastases were recorded in any horse. Nevertheless, these tumours present considerable therapeutic challenges (Dixon and Head ; Witte and Perkins ) as exemplified in two of the reports (Federici et al . ; Fjordbakk et al .…”

“…Dixon and Head (1999) found that just 20% of 28 horses with sinonasal neoplasia had metastases to drainage lymph nodes (although another 42% of affected horses had reactive lymphadenopathy of these lymph nodes) and no distant metastases were recorded in any horse. Nevertheless, these tumours present considerable therapeutic challenges Witte and Perkins 2011) as exemplified in two of the reports (Federici et al 2015;Fjordbakk et al 2015) published in this edition of Equine Veterinary Education. Head and Dixon (1999) noted that the absence of case reports at that time contributed to the lack of advances in equine sinonasal oncology.…”