L61: lymphoma in dogs and cats

what are the causes of enlarged lymph nodes?

1. neoplasia

2. inflammation

3. infection

4. immune mediated

should prednisone be started prior to diagnosis?

no, lymph nodes will shrink and then we cannot get sample to give diagnosis

what size needle do we use for FNA of lymph nodes?

25G

what does the slide show?

inflammation

what does the slide show?

high grade lymphoma

what is PARR?

PCR test used to differentiate between inflammation/infection and cancer

what does a polyclonal population on PARR inform you?

inflammatory or infectious response

what does a monoclonal population on PARR inform you?

cancer

when can false positive occur with PARR?

tick borne diseases (especially Erlichia)

what percent of lymphoblasts will be on the slide to make you think lymphoma?

more than 50%

what does flow cytometry tell you?

differentiates between T cell and B cell neoplasia

what type of lymphoma is most common in dogs?

multicentric high grade lymphoma

what is the most common location for high grade lymphoma in dogs?

mediastinal

what locations can high grade lymphoma occur in dogs?

1. mediastinal

2. cutaneous

3. GI

4. other extranodal sites

what is the most common paraneoplastic syndrome seen in dogs with lymphoma?

anemia

what paraneoplastic syndromes will occur in dogs with lymphoma?

1. anemia

2. hypercalcemia

3. fever

4. cachexia

5. neuropathies

what lymphoma do we commonly associate with hypercalcemia in dogs?

T-cell lymphoma

what is stage 1 lymphoma in dogs?

one lymph node involved

what is stage 2 lymphoma in dogs?

lymph nodes cranial OR caudal to the diaphragm involved

what is stage 3 lymphoma in dogs?

lymph nodes cranial AND caudal to the diaphragm involved

what is stage 4 lymphoma in dogs?

any sites seen in stage 1-3 plus liver OR spleen involvement

what is stage 5 lymphoma in dogs?

involvement of bone marrow or extranodal sites

what is substage A lymphoma in dogs?

no clinical signs of disease

what is substage B lymphoma in dogs?

clinical sigs of disease

what are the preferred diagnostic tests for staging of lymphoma in dogs?

1. CBC/CHEM/UA

2. flow cytometry

what other diagnostic tests may be used for staging of lymphoma in dogs?

1. thoracic radiographs

2. abdominal ultrasound with good view of liver and spleen

3. bone marrow aspirate

what is the most aggressive treatment for canine lymphoma?

CHOP chemotherapy

what is the median survival rate in dogs with B-cell lymphoma that had CHOP treatment?

12-18 months

what is the median survival rate in dogs with T-cell lymphoma that had CHOP treatment?

6 months

what is the intermediate treatment for dogs with lymphoma?

doxyrubicin

what is the median survival rate in dogs with lymphoma that had doxyrubicin for treatment?

6-8 months

what is the least aggressive treatment for dogs with lymphoma?

prednisone

what histopathological grade has a better prognosis for canine lymphoma?

1. low grade

2. small cell

what immunophenotype has a better prognosis for canine lymphoma?

B-cell

what substage has a better prognosis for canine lymphoma?

substage A

what is the prognosis for cranial mediastinal lymph node enlargement in canine lymphoma?

negative prognosis

what is the prognosis for prolonged steroid pretreatment in canine lymphoma?

negative prognosis due to drug resistance

what is the best prognostic factor for canine lymphoma?

response to treatment

what is the common small cell lymphoma seen in dogs?

T zone lymphoma

what do we use to diagnose T zone lymphoma in dogs?

1. PARR

2. flow cytometry

what do we use to treat T zone lymphoma in dogs?

chlorambucil when lymph nodes start to bother the dog

what is the first diagnostic step for high grade canine lymphomas?

1. FNA

2. cytology

what is the most common GI cancer in cats?

feline lymphoma

where can we see feline lymphoma?

1. GI tract

2. extranodal

3. peripheral/nodal

what can directly cause lymphoma in cats?

FeLV

what is important to understand about FIV and lymphoma?

FIV does not directly cause lymphoma

what is the typical work up for an adult vomiting cat?

1. CBC/Chem

2. thyroid panel

3. thoracic radiographs

4. potenitally abdominal radiographs

5. abdominal ultrasound

what do you do after seeing an enlarged lymph node on a cat?

FNA and cytology

what do you do after FNA and cytology in a cat with enlarged lymph node?

perform biopsy to determine if it is IBD or small cell lymphoma

what type of biopsy is needed to differentiate IBD and small cell lymphoma in cats?

1. full thickness via exploratory laparotomy

2. deep endoscopic biopsies

what is the most common site for small cell lymphoma in cats?

GI tract

what is used to diagnose small cell lymphoma in cats?

biopsy

what is used to treat small cell lymphoma in cats?

chloramucil and prednisone

what is the response to treatment in cats with small cell lymphoma?

over 70%

what is the survival time for cats with small cell lymphoma who underwent treatment?

1-2 years

how can large cell lymphomas in cats be diagnosed?

cytology

what is the most aggressive treatment for large cell lymphoma in cats?

CHOP

what is the median survival rate in cats with large cell lymphoma that had CHOP?

6 months

what is the response rate for CHOP in cats with large cell lymphoma?

60%

what is the intermediate treatment for cats with large cell lymphoma?

1. COP

2. doxyrubicin

what drugs are included in COP treatment for cats with large cell lymphoma?

1. cyclophosphomine

2. vincristine

3. prednisone

what is the response to treatment in cats that get COP for large cell lymphoma?

50-60%

what is the survival rate in cats that underwent COP for large cell lymphoma?

3 months

what is the least aggressive treatment for large cell lymphoma in cats?

prednisolone

what is the most common nasal tumor seen in dogs?

nasal adenocarcinoma

what is the most common nasal tumor seen in cats?

nasal lymphoma

what is the typical grade for nasal and paranasal lymphomas in cats?

intermediate to high grade

what is the treatment for nasal lymphoma in cats?

radiation therapy

what is the median survival time for nasal lymphomas in cats?

1.5 years