Case Study

CT – Mycotic rhinitis and complete destruction of conchal and nasal turbinates in a 6 year old MN DSH cat

This 7 year old MN DSH cat presented for a CT of the head

DX

The findings are consistent with mycotic rhinitis and complete destruction of the conchal and turbinate structures in both nasal cavities.

Image Interpretation

CT of the head:

The right frontal sinus is completely filled with non-contrast enhancing soft tissue attenuating material, which is also attached to the ethmoid turbinalia of the caudal compartment of the right nasal cavity. Both nasal cavities present as “empty-nose” with complete destruction of the conchal and turbinate structures. After contrast administration the mucosal lining of both nasal cavities presents marked contrast enhancement and is severely thickened. The bony lining of the right frontal sinus presents marked hyperostosis. The pars orbitalis of the right and left frontal bone present multiple moth-eaten osteolytic areas. In the right orbita, associated with the osteolytic areas a hypoattenuating non-contrast enhancing area is visible, measuring 5x3x10mm in size. The extraocular ocular muscles of the right ocular bulb present a markedly increased volume and contrast enhancement. A moderate right-sided exophthalmos is noted.

Outcome

Even though rare in cats
Aspergillosis appears to be more likely than Crypococcosis based on the typical
imaging findings.
Due to secondary bone destruction of the pars orbitalis of the frontal bone there is a
developing retrobulbar abscess formation present with severe myositis of the
extraocular muscles on the right side.
Recommended rhinoscopy for further evaluation with sampling for culture and
histopathology (detection of fungi microscopically is more straightforward than with
culture in many cases) followed by local and systemic antimycotic therapy. Surgical
treatment of the retrobulbar abscess should be considered paralleling the rhinoscopy
and local antifungal therapy.