Page 771 - Withrow and MacEwen's Small Animal Clinical Oncology, 6th Edition

CHAPTER 33 Hematopoietic Tumors 749

1.000

VetBooks.ir .8750
.7500
Proportion surviving .6250

.5000
.3750

.2500

.1250

0.000
0 120 240 360 480 600 720 840 960 1080 1200
Days from start of treatment
• Fig. 33.30 Survival curve of 37 dogs with multiple myeloma treated with chemotherapy. The median
survival time (MST) is 540 days. (From Matus RE, Leifer CE, MacEwen EG, et al. Prognostic factors for
multiple myeloma in the dog. J Am Vet Med Assoc. 1986;188:1288-1292.)

TABLE 33.17 Classification of Multiple Myeloma in
Cats Based on Clinical and Diagnostic
Criteria Suspected of Predicting
Prognosis 770
Behavior Category Criteria
Aggressive Hypercalcemia, presence of bony lesions
with pathologic fracture, low packed cell
volume (PCV), presence of light-chain
Bence Jones protein in urine, azotemia,
hypercreatinemia, persistence of high
serum protein level after 8 weeks of
treatment, little or no clinical improve-
ment
Less aggressive Normal serum calcium, normal creatinine,
blood urea nitrogen, PCV levels, pres-
ence of bony lesions without patho-
logic fractures, absence of light-chain
Bence Jones protein, normalization of
serum protein level after 8 weeks of
treatment.

• Fig. 33.31 A cutaneous plasmacytoma on the limb of a dog.

Solitary and Extramedullary Plasmacytic (9%; Fig. 33.32), and the gastrointestinal tract (4%). The skin of
Tumors the limbs and head (including the ears) are the most frequently
reported cutaneous sites. 783 Oral plasmacytoma represents 5% of
Solitary collections of monoclonal plasmacytic tumors can origi- oral tumors, 2% of lingual tumors, and approximately 20% of
nate in soft tissues or bone and are referred to as extramedullary all EMPs. 853 Other EMP sites uncommonly encountered include
plasmacytoma (EMP) and solitary osseous plasmacytoma (SOP), spleen, genitalia, eye, uterus, liver, larynx, trachea, third eyelid,
respectively. The systemic, multicentric, biologically aggres- sinonasal cavity (one case reported in the cat 862 ), and intracranial
sive EMP syndrome encountered in cats has been discussed in sites. 863–871 The American cocker spaniel, English cocker spaniel,
the MM section and will only receive limited discussion in this and West Highland white terrier (and perhaps Yorkshire terri-
section. 771,786 A number of large case compilations of cutane- ers, boxers, German shepherds, and Airedale terriers) have been
ous plasmacytoma have been reported in the dog. 774,783,850–861 reported inconsistently to be at increased risk for developing plas-
The most common locations for EMP in the dog are cutaneous macytomas and the median age of affected dogs is 9 to 10 years
(86%; Fig. 33.31), mucous membranes of the oral cavity and lips of age. 783,853