Page 519 - Withrow and MacEwen's Small Animal Clinical Oncology, 6th Edition

CHAPTER 24 Tumors of the Respiratory System 497

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A B

• Fig. 24.5 Radiographs of a dog with an intranasal anaplastic carcinoma. (A) In this open mouth ventro-
dorsal view of the maxilla, note the asymmetry from side to side. A soft tissue opacity in the left nasal cavity
(arrows) suggest the presence of a space-occupying mass. (B) Rostral-caudal skyline view of the frontal
sinuses. A soft tissue opacity in the left frontal sinus suggests extension of tumor or obstructive rhinitis.
(Courtesy Dr. David Jimenez.)

A B

• Fig. 24.6 (A) Several techniques can be used to procure tissue biopsy material from dogs with nasal
tumors. A bulb syringe (a) can be used to flush out tumor material, or a biopsy forcep (b), plastic cannula
(c), or bone curette (d) can be inserted through the nostril. (B) To flush biopsy tissue in an anesthetized dog
with an endotracheal tube, the contralateral passage is occluded, and flushing pressure is created with
a saline-filled bulb syringe; the tissue is flushed back through the nasopharynx and out the mouth into a
collection bowl.

to the medial canthus of the eye (Fig. 24.7). Mild-to-moderate of neoplasia was made in only 56% of the samples on the first
hemorrhage is to be expected and generally subsides within sev- attempt in spite of the presence of a mass lesion seen either on
eral minutes. Inadequate biopsy size or sampling outside the imaging or rhinoscopy. The proportion of first biopsies yielding
region of the tumor may preclude an accurate diagnosis. Further accurate results did not differ between the techniques, indicating
testing may be necessary when clinical and histologic findings that blind biopsy may be as diagnostic as rhinoscopy guided. This
are incongruent. In cases in which imaging results are suggestive study also found that in cases that had both advanced imaging
of an aggressive process, yet histopathologic changes are consis- and rhinoscopy (n = 54), imaging detected a mass in all cases
tent with nonspecific inflammatory disease, repeat biopsy may compared with rhinoscopy, which identified a mass in 41% of
be needed for definitive diagnosis. 27,49 One study evaluated the the cases. 102
diagnostic accuracy of three different biopsy techniques in 117 Attempts at nasal washing and fluid retrieval for cytologic
dogs with confirmed nasal neoplasia. 102 Techniques included examination generally have been unrewarding and are not recom-
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blind biopsy, advanced image-guided biopsy to direct location of mended as the sole means of diagnosis. Brush cytology also has
a blind biopsy, or rhinoscopy guided. For all patients, a diagnosis been described, but it often is not diagnostic. 103