Three horses with bilateral sinonasal progressive haematomas not associated with the ethmoidal labyrinth

Abstract

Summary Progressive haematomata (PH) are a rare cause of equine paranasal sinusitis and are thought to result from recurrent haemorrhage within the respiratory submucosa of the ethmoidal labyrinth. Clinical signs of PH are variable but mostly attributable to rupture of the mass with haemorrhage, occlusion of nasomaxillary drainage and secondary infection. Almost all affected horses have unilateral or bilateral, intermittent, serosanguinous nasal discharge. Radiographic examination is useful in identifying large PH, but small masses can be overlooked because of superimposition. Computed tomography (CT) has the benefit of producing cross‐sectional images of the sinuses, overcoming the limitations of radiography. The cases in this report suffered from bilateral PH not associated with the ethmoidal labyrinth. They highlight the benefit of CT in the diagnosis, surgical planning and evaluation of the architecture of the sinuses. Preoperative treatment with formalin to desiccate the mass prior to removal can be performed more safely when guided by CT.

Progressive ethmoidal haematoma

“…Lesions originating on the nasal mucosa of the ethmoid can be transendoscopically injected on per nasum endoscopy and intrasinus lesions can be treated similarly via sinoscopic portals as described by Barker et al . () in Case 1 . However, for lesions with communication with the infraorbital nerve (as alluded to by Barker et al .…”

“…In addition, extensive lesions may have caused erosion of surrounding bone including to the calvarium ( Fig ) or infraorbital canal (as in Case 3 described by Barker et al . ). Vascular endothelial growth factor has been demonstrated in these lesions in 4 horses (Orsini and Hausner ) but to date their precise aetiology remains elusive.…”

“…Clinical signs including low volume epistaxis are sometimes preceded by a mucoid discharge, and lesions can bleed intermittently and be subclinical or latent on a cursory endoscopic examination (Laing and Hutchins ) as was the case in Case 1 (Barker et al . ) which showed unilateral signs despite being discovered subsequently to be bilaterally afflicted. Bilateral disease was reported in 8 out of 16 horses diagnosed on CT by Textor et al .…”

“…Although the lesions described by Barker et al . () were grossly located distant to the ethmoid labyrinth it is probable that they originated from branches of the same arterial vascular tree, and therefore do not merit a different classification. The use of CT was invaluable in the planning of attempted surgical resection although the authors' claim that it facilitated complete surgical excision is somewhat bold in the absence of marginal histological biopsies, and the recurrence in Case 1 .…”

“…However, for lesions with communication with the infraorbital nerve (as alluded to by Barker et al . ), sphenoidal vascular system or potential penetration of the cribiform plate ( Figs and ), blind transendoscopic injection of formalin should be considered to have significant risk of unpleasant side effects (Frees et al . ).…”