Page 325 - Problem-Based Feline Medicine

17 – THE CAT WITH WEIGHT LOSS AND A GOOD APPETITE 317

ALIMENTARY LYMPHOSARCOMA* Diagnosis
Hematology may reveal non-specific changes includ-
Classical signs ing neutrophilia and lymphopenia. Lymphoblasts may
occasionally be seen in the circulation.
● Usually older cats.
● Anorexia and weight loss, ± vomiting, ± Serum biochemistry may reveal panhypoproteinemia
diarrhea. and/or hyperbilirubinemia.
● Early in disease may have a good appetite.
Most cats test negative for FeLV infection.
Survey radiographs may reveal gas- or fluid-filled
Pathogenesis loops of intestines. Barium studies may reveal floccula-
tion or persistent adherence of the barium to the
Lymphosarcoma is the most common GI neoplasia
mucosa, irregular mucosal surfaces, luminal narrowing
of cats.
or intramural thickening.
Alimentary lymphosarcoma can occur isolated to the
Ultrasound examination may reveal intestinal wall
intestine, or as part of multicentric disease.
irregularity, thickening, or altered echogenicity, and/or
It can occur as a focal lesion or diffuse intestinal enlarged mesenteric lymph nodes, liver or spleen.
thickening. It can arise in the stomach, small intestines
Diagnosis is made by examination of a GI tract fine-
and/or colon, and involvement of the ileocolic junction
needle aspirate or biopsy, with or without biopsies
is common.
from mesenteric lymph nodes and/or other abdominal
● Concurrent involvement of mesenteric lymph
organs.
nodes, liver and/or spleen is not uncommon.
Differentiating lymphocytic (small cell) alimentary
The cells may be lymphocytic, lymphoblastic, of B or
lymphosarcoma from lymphocytic-plasmacytic IBD
T cell origin or, occasionally, large granular lympho-
can be very difficult.
cytes or globular leukocytes.
Determining which types of cells are involved can aid
Lymphoblastic lymphosarcoma are more likely than
in treatment and prognosis (see below).
lymphocytic lymphosarcoma to present as an abdomi-
nal mass.
Alimentary lymphosarcoma may arise secondary to Differential diagnosis
chronic lymphocytic-plasmacytic IBD.
These include most of the other causes of weight loss
with a good appetite. However, since cats with alimen-
tary lymphosarcoma usually develop vomiting and/or
Clinical signs
diarrhea, other causes of enteropathy, IBD, cholan-
Typically seen in older cats of any sex or breed. giohepatitis, pancreatitis, hyperthyroidism and the
other malassimilation syndromes should be consid-
History usually includes anorexia and weight loss,
ered as important differentials.
but early in the disease the appetite may be good.
Vomiting and/or diarrhea may or may not be
present.
Treatment
Some cats develop fever, ascites or jaundice, and at this
Localized alimentary lymphosarcoma may respond to
stage they rarely maintain a good appetite.
surgical resection and adjunct chemotherapy.
Physical examination typically reveals a thin cat ● Large masses involving the entire thickness of the
with a palpable abdominal mass(es) and/or thick- bowel wall should not be treated with chemother-
ened intestines. apy alone as this may result in gut perforation.