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Lymphoma, Multicentric (Dog) 609

• FeLV status does not appear to influ- • A variety of prognostic factors has been iden- SUGGESTED READING
ence rates of response to chemotherapy, tified that may help predict an individual’s Vail DM: Feline lymphoma and leukemia. In
VetBooks.ir shorter remission and survival times, pos- • An understanding of the relative efficacy and Small animal clinical oncology, St. Louis, 2013, Diseases and Disorders
response to treatment and guide the decision
but FeLV-positive cats have significantly
Withrow SJ, et al, editors: Withrow & MacEwen’s
about whether to pursue treatment.
sibly due in part to concurrent FeLV-related
Saunders, pp 638-653.
potential toxicoses of the various protocols
diseases.
aids in determining the best treatment AUTHOR: Laurel E. Williams, DVM, DACVIM
EDITOR: Kenneth M. Rassnick, DVM, DACVIM
PEARLS & CONSIDERATIONS protocol for an individual animal.
Comments Technician Tips
• Lymphoma is a common feline malignancy. Technicians handling chemotherapeutic drugs
• The majority of cats can achieve complete must have received appropriate training regard-
or partial remission when treated with che- ing drug handling, avoidance of unintended
motherapy, and treatment can be rewarding exposure, proper disposal, management of spills,
for the pet owner and veterinarian. and other complications.

Lymphoma, Multicentric (Dog) Client Education
Sheet

BASIC INFORMATION ASSOCIATED DISORDERS PHYSICAL EXAM FINDINGS
Hypercalcemia secondary to elaboration of • Marked generalized lymphadenopathy is most
Definition parathormone–related protein (PTH-rP) by common physical exam finding, although
Well-recognized systemic malignant neoplasm tumor cells occasionally, dogs present with only single
of lymphoid origin or regional lymph node enlargement or
Clinical Presentation single organ (e.g., spleen, gastrointestinal
Synonyms DISEASE FORMS/SUBTYPES tract, thymus) involvement with or without
Lymphosarcoma, malignant lymphoma, non- • Histologic grade regional lymph node enlargement.
Hodgkin lymphoma (human) ○ High-grade or lymphoblastic lymphoma: • Hepatosplenomegaly may be noted in dogs
most common; rapid onset and progres- with visceral involvement.
Epidemiology sion; affected cells are large and blastic in • Other findings, including dyspnea, fever,
SPECIES, AGE, SEX appearance. neurologic signs, may be reflective of other
• Most common canine hematopoietic ○ Low-grade or lymphocytic lymphoma: organ involvement or disease complications.
malignancy: reported incidence of 24-114 rare; chronic insidious onset; affected
cases per 100,000 dogs cells are well differentiated and similar Etiology and Pathophysiology
• Typically middle-aged to older dogs, although in appearance to small lymphocytes. • Rapid onset and disease progression due to
may develop at any age • Stage: based on disease location/extent (e.g, malignant lymphocytes
• No sex predisposition lymph node, liver, spleen) • If untreated, most dogs succumb to disease
in 1-2 months.
GENETICS, BREED PREDISPOSITION HISTORY, CHIEF COMPLAINT
• Several breeds reported to be at increased • Generalized lymphadenopathy most common DIAGNOSIS
risk, including golden retrievers, boxers, • Owners usually report rapid increases in
rottweilers, Scottish terriers, basset hounds, lymph node size over days to a few weeks. Diagnostic Overview
cocker spaniels, German shepherds, Airedales, • Lymph nodes generally are not painful, and Diagnosis suspected based on marked gen-
bulldogs, and poodles; certain breeds (e.g., dogs usually appear otherwise healthy in early eralized lymphadenopathy with minimal to
boxers) may be more likely to develop T-cell stages of disease. no associated clinical signs in an otherwise
lymphoma. • Some patients present with nonspecific signs healthy, middle-aged to older dog; confirmation
• Genetic predisposition reported for a pedigree such as anorexia, weight loss, vomiting, begins with cytologic analysis of affected lymph
of bullmastiffs and a family of rottweilers diarrhea, dyspnea, fever, or polyuria. node.
and otter hounds
Lymphoma Staging
RISK FACTORS
• Reported association with 2,4-D herbicide Stage Characteristics
use, but subsequent study nonconfirmatory
• Reported positive association with electro- I Single lymph node
magnetic radiation exposure II Multiple regional lymph nodes
• Residing in industrial areas and use of paints III Generalized lymphadenopathy
or solvents by owners reported to increase IV Hepatic and/or splenic involvement (± stages I-III)
risk of lymphoma by 8.5- and 4.6-fold,
respectively. V Involvement of bone marrow, blood, and/or any nonlymphoid organ (± stages I-IV)
• Reported associations between hazardous Substage a No overt clinical signs of disease
waste emissions and lymphoma and for Substage b Overt clinical signs of disease
secondhand smoke and lymphoma in Italy

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