Page 47 - Atlas of Small Animal CT and MRI

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Figure 1.2.15 Ceruminous Adenocarcinoma (Canine) CT

(a) CT, TP (b) CT+C, TP
11y FS Lhasa Apso with a previously diagnosed right‐sided ceruminous gland adenocarcinoma that was partially excised as part of an
external ear canal ablation 1 year prior to the CT scan. Complete osteolysis of the tympanic bulla and partial osteolysis of the petrous
temporal bone are evident on the unenhanced CT image (a). A large soft‐tissue mass is present adjacent to the skull base, causing
laryngeal displacement to the left of midline. Mass margins are ill defined, and normal fascial planes are obscured. The mass enhances
on the contrast‐enhanced image (b). Margins are moderately well defined, but there is intracranial extension of the mass through the
petrous temporal bone defect.

Figure 1.2.16 Squamous Cell Carcinoma (Canine) CT

(a) CT, TP (b) CT+C, TP
12y FS Golden Retriever with a mass associated with the right ear. A large, irregularly margined mass arises from the right middle ear (a).
The external ear canal is not evident, and osteolysis of portions of the tympanic, petrosal, and squamous parts of the temporal bone is
seen. The mass moderately and heterogeneously contrast enhances, and the bulk of the mass appears to be contained by the residual
bulla and grossly distended external ear canal (b: arrowheads). There is also intracranial extension of the mass through a fenestration in
the temporal bone (b: arrow). Ill‐defined contrast enhancement is also present in peritumoral tissues. Biopsy of the mass revealed aural
squamous cell carcinoma.

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