Prioritized your differential in feline ear canal tumor....

VRU 2024

Megan Wisnoski1 Christine Gremillion1 Gwendolyn Levine1 Cambridge Coy1 Kaylynn Veitch2 KennethWaller2 John F. Griffin IV1

Background
Feline ear canal neoplasia is a rare condition, accounting for 1–2% of all feline tumors and having a high malignancy rate (>80%). Common malignant tumors include ceruminous gland adenocarcinoma and squamous cell carcinoma (SCC). This study aimed to characterize the computed tomographic (CT) features of histopathologically confirmed feline ear canal neoplasia to aid diagnosis and treatment planning.

Methods
This retrospective, multicenter study included 25 cats with histologically confirmed ear canal neoplasms from Texas A&M University and the University of Wisconsin. CT scans were analyzed by two veterinary radiologists for mass characteristics, attenuation, contrast enhancement patterns, involvement of adjacent structures, and regional changes. Diagnoses were categorized as malignant ceruminous gland neoplasia (MCGN), ceruminous gland adenoma (CGA), SCC, or other.

Results
Demographics:
-MCGN: 14 cats (median age: 12 years).
-CGA: 6 cats (median age: 10.5 years).
-SCC: 3 cats (median age: 8 years).
-"Other" group: 2 cats.

CT Findings:
-CGA: Typically homogeneous attenuation and contrast enhancement, with no intralesional fluid accumulation (IFA) or adjacent structure involvement.
-MCGN: Variable attenuation and contrast enhancement; occasional IFA and adjacent structure involvement.
-SCC: Consistently heterogeneous attenuation and contrast enhancement, with frequent IFA, osteolysis, and invasion of surrounding structures.
-Shared features: All neoplasms were soft tissue-attenuating and contrast-enhancing; lymphadenopathy was common across groups.

Distinguishing Features:
-Homogeneous attenuation and contrast enhancement favored CGA.
-Heterogeneous attenuation, IFA, and osteolysis suggested malignancy, especially SCC.

Limitations
The retrospective design prevented standardization of CT acquisition protocols.
Small sample size, particularly for SCC, limits generalizability.
No analysis of CT diagnostic accuracy or correlation with outcomes.

Conclusions
CT imaging provides valuable insights into feline ear canal neoplasia, although significant overlap exists between benign and malignant types. Features like attenuation uniformity and involvement of adjacent structures can aid differentiation. Biopsy remains essential for definitive diagnosis. Further studies should focus on diagnostic accuracy and prospective evaluations of treatment outcomes.

Twelve-year-old castrated male domestic shorthair with a malignant ceruminous neoplasm. A, Precontrast soft tissue transverse CT image. The left external ear canal is filled with soft tissue and fluid-attenuating material. B, Postcontrast soft tissue transverse CT image. This mass (asterisks) has homogeneous attenuation, moderate to marked, heterogeneous contrast enhancement, an irregular luminal margin, and shares a broad margin with the vertical ear canal wall.

How did we do?

Login or Subscribe to participate in polls.

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.