Sophie Favier 1 2, Pierre P Picavet 1 3, Emilie Pierrot 1, Marianne Heimann 4, Géraldine Bolen 1
Background
Osteochondromatosis is a rare, benign bone disorder involving multiple osteochondromas and has been documented in various species, including cats. While osteochondromas have been reported in many skeletal locations, involvement of the hyoid bone is extremely rare and unreported in felines. This case describes the CT features of a feline hyoid osteochondroma in a FeLV-positive cat with concurrent skeletal lesions and clinical signs of stridor.
Methods
A 2-year-old male European Shorthair cat with a 3-month history of multiple hard bony proliferations and a 2-week history of stridor underwent radiographic and computed tomography (CT) evaluation. Fine needle aspiration and core biopsies were performed, followed by histopathological analysis. CT scanning was conducted under general anesthesia using a 64-slice CT scanner with reconstructions in bone, soft tissue, and lung windows.
Results
CT revealed multiple smooth bone masses in the ribs, spine, and limbs. A key finding was a homogeneous osseous mass arising from the left epihyoid bone, partially narrowing the laryngeal lumen. A second mass on the calvarium displaced the cerebellum, and a vertebral mass impinged on the spinal canal. Histopathology confirmed benign osteochondromatous proliferation with trabecular bone and cartilaginous components, consistent with osteochondromatosis. Surgical removal was declined due to expected recurrence and disease progression. The cat was euthanized due to worsening respiratory symptoms.
Limitations
No biopsy was performed on the hyoid lesion, although imaging and the similarity to other biopsied lesions suggested a common etiology. Dynamic airway evaluation was limited due to the use of general anesthesia, preventing confirmation of dynamic obstruction. This single case report limits generalizability, and FeLV's causal role remains speculative.
Conclusions
This is the first report of hyoid involvement in feline osteochondromatosis confirmed by CT and histopathology. Hyoid osteochondroma should be included in the differential diagnosis of stridor in cats with skeletal lesions. Whole-body cross-sectional imaging is recommended for comprehensive assessment in such cases, as involvement of anatomically critical areas may significantly impact prognosis.
Transverse CT image reconstructed in a bone window at the level of the larynx, showing a bone mass (M) arising from the left epihyoid bone (arrow). This mass is homogeneous with loss of delineation of the adjacent left epihyoid bone. The lumen of the larynx (*) is barely narrowed by the mass. The edge of the calvarium bone mass is also visible (<).
How did we do?
Disclaimer: The summary generated in this email was created by an AI large language model. Therefore errors may occur. Reading the article is the best way to understand the scholarly work. The figure presented here remains the property of the publisher or author and subject to the applicable copyright agreement. It is reproduced here as an educational work. If you have any questions or concerns about the work presented here, reply to this email.
