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Cardiac Neoplasia

Key Points

• Benign and malignant tumors of the cardiovascular system are rare in cats.
• The most common types are lymphoma and aortic body chemodectoma; the latter appears to occur more commonly than was
previously reported.
• Cardiac tumors in cats are more commonly associated with respiratory or nonspecific signs of ill thrift, or they may be
incidental findings at necropsy.
• The prognosis is generally poor, although successful regression of lymphoma with standard chemotherapy has been reported.

INTRODUCTION The etiology of these tumors is unclear, with the
exception of lymphoma, which can be caused by the
Cardiac tumors (cardiac neoplasms) are uncommon feline leukemia virus (FeLV).
diseases in feline cardiology. Nevertheless, certain char- Gross lesions are characteristic of the tumor type.
acteristics appear to separate this location of neoplasia Lymphoma may affect the heart diffusely (Liu et al.
from its equivalent in other species. In contrast to dogs, 1989; Brummer and Moïse 1989) or focally (Shinohara
for example, cardiac hemangiosarcoma is extremely rare et al. 2005) (Figure 16.1). It is almost always identifiable
in the cat. Lymphoma and chemodectoma, however, are in other tissues once the diagnosis of cardiac lymphoma
well-recognized, and although large case series do not is made. Chemodectoma may affect the carotid body (2
exist, some observations have been made allowing reported cases) or the aortic body (heart base; 13
limited conclusions to be drawn.
reported cases). These heart base masses are located
between the aorta and either atrium; one was found
PREVALENCE, ETIOLOGY, PATHOPHYSIOLOGY, adjacent to the cranial vena cava.
AND GROSS PATHOLOGY
Cardiac neoplasia encompasses primary tumors of the SIGNALMENT
heart and secondary tumors, which originate elsewhere Cardiac lymphoma is described in cats of all ages (5–13
and metastasize to the heart. Historically, primary years of age when noted in case reports) and both
cardiac tumors were considered very rare in cats (e.g., genders. Chemodectoma is similarly described in adult
n = 1/30, 3% in one case series) (Aupperle et al. 2007). cats (4–13 years old) of both genders.
Several recent case reports of chemodectoma in the cat
seem to alter this prevalence, and greater attention has HISTORY AND CHIEF COMPLAINT
been devoted lately to these heart base tumors (e.g., 7
cases published in 1994–2004 versus 2 cases in a search In dogs, cardiac tumors routinely cause clinical signs via
of the Veterinary Medical Database covering 210,888 pericardial effusion producing signs of cardiac tampon-
feline admissions from 1982–1993) (Ware 1995). ade such as acute collapse and abdominal distension

Feline Cardiology, First Edition. Etienne Côté, Kristin A. MacDonald, Kathryn M. Meurs, Meg M. Sleeper.
© 2011 John Wiley & Sons, Inc. Published 2011 by John Wiley & Sons, Inc.

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