This patient presents to your clinic for a 2 month history of unilateral epistaxis. Previous antifungal flush of the guttural pouch did not resolve clinical signs.
Findings
Most evident on the dorsoventral projections, there is an ill-defined increase in soft tissue opacity in the region of the left ethmoid bones. Immediately rostral to this opacity, there is a large, well-defined 13.0 x 10.4 x 8.4 cm soft tissue opaque mass. This mass extends to involve the left conchofrontal and left maxillary sinuses. No osseous abnormalities are noted. The occlusal surface of the maxillary and mandibular premolar and molar teeth are mildly irregular. The remaining features of the dental structures are within normal limits.
Diagnosis
Soft tissue mass consistent with the endoscopically diagnosed ethmoid hematoma.
Mild premolar and molar occlusal abnormality, consistent with excessive transverse ridges.
Conclusions
Progressive Ethmoid Hematoma
Progressive ethmoid hematoma (PEH) is a vascular anomaly that arises from the ethmoid region. It grows via hemorrhage and follows the path of least resistance. This growth can occasionally lead to pressure necrosis of the surrounding bone.
PEH is most often unilateral but can progress to bilateral or, less often, begin as two distinct bilateral lesions. Bilateral lesions have been reported in up to 16% of horses with PEH.
PEH has been divided into four forms based on anatomic involvement: maxillary sinus, ethmoid turbinate, nasal passage, and sphenopalatine sinus.
Clinical signs of PEH most often include epistaxis and respiratory noise. These are more commonly seen with more advanced disease. Other clinical signs can include coughing, facial swelling/deformity, head shaking, and malodorous breath.
PEH is seen most often in middle-aged horses, with Thoroughbreds and Arabians overrepresented.In one study of 277 horses with sinonasal disease, progressive ethmoid hematoma had an incidence rate of 7.9%. 2 horses with PEH in that study had secondary mycotic infections.
PEH is often tentatively diagnosed based on history, clinical signs, radiographic, and endoscopic findings. A unilateral, multicolored lesion is characteristic of PEH, but histopathology is required for definitive diagnosis.
Differential list for PEH should include paranasal sinus cyst, nasal polyp, and neoplasia.
PEH treatment ranges from minimally invasive procedures such as sinoscopically guided formalin injection to more invasive surgical excision.
The number of treatments required may vary, but one study showed no recurrence of clinical signs 33 months in the majority of cases with a median of 2 treatments (range 1-6). More treatments were usually associated with bilateral disease or development of secondary empyema or mycotic infections.
References
Dixon, P. M., Parkin, T. D., Collins, N., Hawkes, C., Townsend, N., Tremaine, W. H., et al. (2011). Equine paranasal sinus disease: A long-term study of 200 cases (1997-2009): Ancillary diagnostic findings and involvement of the various sinus compartments. Equine Veterinary Journal, 44(3), 267–271.
Dixon, P. M., Parkin, T. D., Collins, N., Hawkes, C., Townsend, N., Tremaine, W. H., et al. (2011). Equine paranasal sinus disease: A long-term study of 200 cases (1997-2009): Treatments and long-term results of treatments. Equine Veterinary Journal, 44(3), 272–276.
Gasser, A. M., Love, N. E., Tate Jr, L. P. (2000). Radiographic Diagnosis – Ethmoid Hematoma. Veterinary Radiology & Ultrasound, 41, 247-249.
Tremaine, W. H., Dixon, P. M. (2001). A long-term study of 277 cases of equine sinonasal disease. Part 1: Details of horses, historical, clinical and ancillary diagnostic findings. Equine Veterinary Journal, 33(3), 274–282.
Tremaine, W. H., Dixon, P. M. (2001). A long-term study of 277 cases of equine sinonasal disease. Part 2: Treatments and results of treatments. Equine Veterinary Journal, 33(3), 283–289.
