Progressive Ethmoidal Haematoma

• Slowly expanding non-neoplastic mass of horses
• Originates from submucosa of ethmoidal labyrinth
• Either from nasal or sinusal portion of ethmoid labyrinth
• Unilateral, can extend to nostrils or choanae
• Rarely elsewhere in sinuses
• Expands to nasal cavity, paranasal sinuses, nasopharynx causing destruction of tissue
• Micro - haemorrhage, calcification of connective tissue fibres
• Aspergillus spp. may be present on the lesion
• May cause epistaxis
• Can recur after surgical excision
• May arise subsequently to chronic inflammation