Page 1216 - Cote clinical veterinary advisor dogs and cats 4th

606 Lymphoma, Gastrointestinal

• Managing anemia with transfusions and ○ Because of the high likelihood of systemic • Anatomic location may have prognostic
hematinics as needed (p. 1169) or local spread, these animals are followed significance for dogs. Colonic lymphoma
VetBooks.ir • Analgesics as indicated for pain • Cobalamin supplementation as needed • Cats with low-grade GI LSA require minimal
with a course of chemotherapy.
is associated with a better prognosis than
• Antibiotics and emergency management for
gastric or jejunal lymphoma.
peritonitis (p. 779)
(p. 183)
• Promotility agents are contraindicated in
obstructive disease. Nutrition/Diet therapy and may survive for years using treat-
ment with chlorambucil, prednisolone, and
• Management of hypercalcemia of malig- These animals are often thin; efforts should be cobalamin repletion.
nancy (pp. 491 and 754) by IV fluids and made to provide adequate nutritional support. • Antibiotic therapy (e.g., tylosin) for second-
furosemide 1-2 mg/kg IV or PO q 12-24h Appetite often improves if disease can be placed ary dysbiosis may be helpful.
after rehydration, bisphosphonates (e.g., in remission.
pamidronate, zoledronate), or possibly PEARLS & CONSIDERATIONS
calcitonin 4-8 IU/kg IV, IM, or SQ q 12h Possible Complications
acutely. Management of hypercalcemia by • Surgical wound dehiscence with secondary Comments
treating the underlying malignancy should peritonitis, pneumoperitoneum • Full-thickness surgical biopsies may be
be started only after the cytologic or histo- • Chemotherapy-induced neutropenia can pre- necessary to diagnose small-intestinal LSA
pathologic diagnosis of GI LSA is established dispose to infection, and thrombocytopenia because endoscopic access is limited to the
because treatment with glucocorticoids or can increase risk of hemorrhage. duodenum or ileum.
other lympholytic agents can compromise • Chemotherapy can result in perforation of • Fine-needle aspiration cytology of the
detection of lymphoma. transmural lesions. intestinal wall is possible, but low-grade
LSA is difficult to differentiate from reactive
Chronic Treatment Recommended Monitoring lymphocyte expansion.
• Chemotherapy is generally the treatment of • CBC for chemotherapy-induced myelosup- • In general, the underlying cause of refrac-
choice for GI LSA. A number of chemo- pression tory diarrhea should be pursued aggressively
therapy protocols (pp. 607 and 609) have • Ultrasonography is most practical for detect- because GI LSA is an important differential
been used to treat GI LSA. ing intraabdominal metastasis or recurrence diagnosis.
• For high-grade disease, the University of and may identify small amounts of peritoneal • Treatment with glucocorticoids may impede
Madison-Wisconsin or similar CHOP-based fluid as the first manifestation of peritonitis the accurate diagnosis of LSA because
(cyclophosphamide, doxorubicin, vincristine, in cases of bowel rupture. lymphoblasts are rapidly lysed.
prednisone/prednisolone) protocols involve • Periodic restaging (physical exam monthly,
○ Sequential treatment with CHOP drugs laboratory evaluation, thoracic radiographs, Prevention
± L-asparaginase over 19-25 weeks abdominal ultrasound exam every other • Aggressive management of lymphoplasma-
○ Single-agent doxorubicin, mitoxantrone, month) for patients in complete remission cytic enteritis is recommended. IBD may
ifosfamide, or lomustine and combination after surgical excision or completion of dose- progress to GI LSA.
therapy with doxorubicin/dacarbazine intense therapy with CHOP-based protocols. • Limiting exposure to lawn and agricultural
have been used as rescue agents. chemicals and second-hand smoke is likely
• For low-grade disease, treatment with PROGNOSIS & OUTCOME beneficial, but no specific preventive measures
milder chemotherapy protocols is helpful in are known.
prolonging life with good quality. Low-grade • GI LSA is a serious, life-threatening illness,
protocols include but because of the widely different biological Technician Tips
2
○ Chlorambucil (commonly 20 mg/m PO q behaviors of various subtypes, predicting These patients are very ill. Monitor for signs
14 days [p. 609] or 2 mg PO q 48h) and therapeutic response and duration of survival of hypotension and abdominal effusion that
prednisolone (various dosing schemes but is difficult for individual animals. might indicate GI perforation.
often starting with 1-2 mg/kg PO q 24h • In general, low-grade disease is indolent
for 7-14 days, then reducing to 0.5-1 mg/ and associated with longer survival than Client Education
kg PO q 48h), or COP (cyclophospha- high-grade disease, depending on extent of Response to initial therapy can be the best
mide, vincristine, and prednisolone) disease at the time of diagnosis. prognostic indicator.
• One study suggests lomustine as a rescue agent • T-cell phenotype is generally less respon-
for cats with resistant small or intermediate sive and associated with shorter survival SUGGESTED READING
cell GI LSA achieves a longer progression-free duration than B-cell disease. Historically, WSAVA International Gastrointestinal Standardiza-
interval than for large cell GI LSA. median survival times for extranodal T-cell tion Group: ACVIM consensus statement: endo-
• Abdominal radiation therapy as a rescue lymphomas were typically 6 months or less scopic, biopsy, and histopathologic guidelines for
protocol for feline GI LSA appears to be well in dogs. the evaluation of gastrointestinal inflammation in
tolerated and may increase median survival • Treatment efficacy remains variable, with companion animals. J Vet Intern Med 24:10, 2010.
time. reported median remission times of 3-12 AUTHOR: Barbara E. Kitchell, DVM, PhD, DACVIM
○ Abdominal irradiation may be incorpo- months. EDITOR: Rance K. Sellon DVM, PhD, DACVIM
rated into the induction protocol. This • Failure to achieve remission and diarrhea
is particularly helpful for cats that resist at presentation are negative prognostic
oral medication. indicators.
• Curative therapy for focal GI LSA lesions
is through complete surgical excision.

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