Lymphoma & Leukemia Flashcards
What are the cells of origin of lymphoma? What is the typical presentation?
B and T lymphocytes
- typically no clinical signs
- generalized peripheral lymphadenopathy +/- hepatosplenomegaly
What are the 5 clinical stages of canine lymphoma? What are the substages?
- only 1 peripheral LN enlarged
- multiple enlarged peripheral LNs on the same side of the diaphragm
- multiple enlarged peripheral LNs on both sides of the diaphragm
- liver and/or spleen involvement
- any other organ involvement, commonly BM, lung, and kidneys
healthy vs. sick
How is cytology used to diagnose lymphoma?
FNA of an enlarged peripheral LN shows lymphoblasts
- careful manipulation of slides to avoid rupture of cells
What is seen on CBC/chem/UA in cases of lymphoma?
often WNL
- lymphoblasts on smear
- mild anemia
- elevated ALP/ALT
- hypercalcemia with T-cell lymphoma
What are some findings on thoracic radiographs and abdominal ultrasounds that can support a diagnosis of lymphoma?
THORACIC RADS = cranial mediastinal mass, perihilar lymphadenopathy, pulmonary parenchymal involvement
ABDOMINAL U/S = hepatomegaly, splenomegaly, enlarged sublumbar or mesenteric LNs
What is the purpose of phenotyping lymphoma? What are 2 options?
determine B-cell vs T-cell
- PARR assay - when cytology is not conclusive
- flow cytometry - determines size of neoplastic lymphocytes, can also diagnose indolent lymphoma
What is the prognosis of canine lymphoma like? What are some less aggressive forma?
typically not curable, no therapy = 6-8 weeks; typically responds well to treatment
- indolent lymphoma
- small cell lymphoma
What is the most common protocol for treating canine lymphoma? What are the 2 versions? What is the MST on this treatment?
CHOP —> cyclophosphamide, doxorubicin, vincristine, prednisone
- UW-19 = 16 treatments over 19 weeks
- UW-25 = 16 treatments over 25 weeks
12 months
What are 2 chemotherapies that can be used as core treatments of canine lymphoma? What is commonly given concurrently?
- Doxorubicin - q 3 weeks for 5 doses (MST = 7-9 months)
- CCNU - q 3 weeks continually (MST = 4-6 months)
prednisone
What is the purpose of turning to single agent therapy in cases of canine lymphoma over CHOP?
- decrease severity of side effects, like GI signs and neutropenia
- rescue after CHOP failed
What is a new veterinary-only chemotherapy agent available for canine lymphoma? What is its mechanism of action?
Tanovea (rabacfosadine) - q 3 weeks for 5 doses, MST = 6-9 months —> may be the nest rescue drug
guanine nucleotide analog - inserts into DNA, resulting in cell death during S phase
What is prednisone like as a single agent in treating canine lymphoma?
- daily, continuous
- easy and inexpensive
- 2-3 month MST
What are the most common signs associated with GI lymphoma? How does it respond to therapy?
severe vomiting, diarrhea, and weight loss; typically does not infiltrate peripheral LNs
poorly —> CCNU preferred, MST of 3-4 months
What are the most common signs associated with cutaneous lymphoma? How does it respond to therapy?
- diffuse flaking/crusting and ulceration of the skin
- severe pruritis
- mild peripheral lymphadenopathy
poor response to CHOP —> CCNU + prednisone with MST of 3-6 months
How is feline lymphoma categorized?
based on anatomical location
- GI
- renal
- nasal
- mediastinal
What are the 2 categories of feline GI lymphoma?
- LARGE CELL - more acute signs of decreased appetite, vomiting, and diarrhea with palpable mid-abdominal mass (SI + mesenteric LN)
- SMALL CELL - more chronic signs of decreased apetite, vomiting, diarrhea, and constipation with a RARELY palpable mid-abdominal mass (SI thickening + LNs)
How are the 2 types of feline GI lymphoma diagnosed?
LARGE CELL = U/S guided FNA of mass
SMALL CELL = full thickness biopsy of small intestinal wall + PARR assay if inconclusive (poor sensitivity in cats)
How do the treatments of the 2 types of feline GI lymphoma compare?
LARGE CELL = CHOP (prednisolone preferred in cats!), COP, cyclophosphamide/doxorubicin/prednisone (single-agent) —> MST of 6-9 months with CHOP
SMALL CELL = chlorambucil + prednisolone, pred alone, CCNU or cyclophosphamide rescue —> MST of 18 months to 3 years depending on resolution of GI signs
How do feline patients with renal lymphoma commonly present? How is it diagnosed?
decreased appetite, lethargy, and vomiting with severely bilaterally enlarged kidneys appreciated on PE
U/S guided FNA of kidneys
What are 4 treatment options for feline renal lymphoma? What is prognosis like?
- CHOP
- COP
- single agent cyclophosphamide
- prednisolone alone
poor —> transient response to therapy with MST of 3-4 months
How do feline patients with nasal lymphoma present? How is it diagnosed?
- nasal congestion, discharge, epistaxis, sneezing +/- facial distortion
- previous treatment of upper respiratory infection with variable success
- anatomically confined, not common for other organs to be involved
CT scan +/- biopsy (can be inconclusive due to inflammation)
What are 5 treatment options for feline nasal lymphoma? What is prognosis like?
- radiation therapy (more confined!)
- CHOP
- COP
- single agent cyclophosphamide
- prednisolone alone
generally good response to therapy —> MST 1-2 years
How do feline patients typically present with mediastinal lymphoma? In what cats is this most common? How is it diagnosed?
acute onset tachypnea/dyspnea
young, FeLV+ cats —> not common these days
thoracic radiographs and cytology of cranial mediastinal mass (large lymphocytes)
What are 5 options for therapy of feline mediastinal lymphoma? What is prognosis like?
- CHOP
- COP
- single agent therapy (not commonly successful)
- prednisolone alone
- radiation if no other organs involved
poor/transient response to therapy —> MST 3 months (better if FeLV-)
What animals are most commonly affected by acute lymphoblastic leukemia (ALL)? How do they present?
younger cats and dogs < 4 y/o
sick on presentation - lethargic, anorexia, vomiting, diarrhea, lameness, fever
What 4 characteristics are used to differentiate ALL from stage V lymphoma?
- acute onset of clinical signs
- lymphadenopathy not common
- poor response to chemotherapy
- short survival times
+ EXTREME leukocytosis
What are the 6 most common findings on clinical pathology associated with ALL?
- greatly elevated WBCs - large lymphoblasts counted as monocytes
- lymphoblasts in BM
- nonregenerative anemia
- moderate to severe thrombocytopenia
- elevated liver enzymes
- increased BUN
What treatment is used for ALL? What is prognosis like?
CHOP + rescue protocols
short-term response to therapy —> poor prognosis
What animals are most commonly affected by chronic lymphocytic leukemia? How do they present?
older dogs and cats
not sick on presentation - often an incidental finding and difficult to differentiate from small cell or indolent lymphoma
What are the 2 most common clinical pathology findings in cases with CLL?
- variably elevated lymphocytes - these neoplastic lymphocytes are commonly able to be counted as lymphocytes (compared to ALL)
- excessive small lymphocytes in BM
often no other significant findings!
What is the most common treatment plan used for CLL?
monitor without treatment
- often incidental!!
What are the 2 major indications for treating CLL? Why is it important to treat at this point? What is considered the best treatment?
- lymphocyte count > 50000/uL
- disease causing illness
at this point, it can mutate into more aggressive disease
chlorambucil + prednisone —> offers control for years
