Page 401 - Problem-Based Feline Medicine

20. The cat with enlarged lymph nodes

Anthony Abrams-Ogg

KEY SIGNS
● Hyperplasia, neoplasia, lymphadenitis most common.
● Edema, vascularization, infarction less common.
● Biopsy and culture lymph node.

MECHANISM?
● Reactive lymphoid hyperplasia, neoplasia or lymphadenitis are the most common causes of
lymphadenopathy.

WHERE?
● Peripheral (superficial) lymph nodes – enlargement may be confined to a solitary/local node, or
be regional or generalized.
There may be accompanying internal (deep) lymphadenopathy.
WHAT?
● The most common causes of generalized lymphadenopathy are generalized skin diseases,
retroviral infections and lymphoma. The most common causes of local and regional
lymphadenopathy are bacterial and fungal infections in the area drained by the node(s). All
causes may result in mild to marked lymphadenopathy.

QUICK REFERENCE SUMMARY

Diseases causing enlarged lymph nodes
MECHANICAL
● Obstructive edema* (p 411)
Local or regional lymphadenopathy occurs due to nodal edema and/or hyperplasia, secondary to
obstructive edema from a tumor or other mass involving the head, neck or a limb.

NEOPLASTIC
● Nodal lymphoma* (p 403)
Regional (head and neck) or generalized (multicentric) lymphadenopathy occurs with predomi-
nance of lymphoblasts on biopsy. Average age of cats with multicentric lymphoma is 4 years. Age

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