Changes

Also known as: '''''Lymphosarcoma — Malignant Lymphoma'''''

Also known as: '''''Lymphosarcoma — Malignant Lymphoma'''''

::Multicentric - Widespread involvement of lymph nodes.

::Multicentric - Widespread involvement of lymph nodes.

::Cutaneous lymphoma - Usually presents as generalised skin disease, but is a malignant transformation of T cells with a propensity for  epithelial sites.

::Cutaneous lymphoma - Usually presents as generalised skin disease, but is a malignant transformation of T cells with a propensity for  epithelial sites.

:'''Type of lymphocyte''' - [[T cells|T-cell]], [[B cells|B-cel]] or [[Natural Killer cells|NK-cell]]

:'''Type of lymphocyte''' - [[T cells|T-cell]], [[B cells|B-cell]] or [[Natural Killer cells|NK-cell]]

:'''Time scale''' - Acute or Chronic

:'''Time scale''' - Acute or Chronic

'''Dogs'''

'''Dogs'''

:Canine lymphoma is most commonly'''multicentric''', therefore the ideal method for collecting a sample for cytological examination is '''fine needle aspiration of the lymph nodes'''. Ideally samples should come from '''multiple nodes''' to give a representative sample. '''Popliteal''' and '''prescapular lymph nodes''' are easily accessible and therefore ideal for sampling. Submandibular lymph nodes should be avoided where possible as they are commonly enlarged and reactive as a result of dental disease. It should be noted that canine lymphoma can occur in any organ containing lymphoid tissue.

:Canine lymphoma is most commonly '''multicentric''', therefore the ideal method for collecting a sample for cytological examination is '''fine needle aspiration of the lymph nodes'''. Ideally samples should come from '''multiple nodes''' to give a representative sample. '''Popliteal''' and '''prescapular lymph nodes''' are easily accessible and therefore ideal for sampling. Submandibular lymph nodes should be avoided where possible as they are commonly enlarged and reactive as a result of dental disease. It should be noted that canine lymphoma can occur in any organ containing lymphoid tissue.

'''Cats'''

'''Cats'''

===Staging===

===Staging===

A staging system is used for lymphoma (Owen, 1980):

A staging system is used for multicentric lymphoma (Owen, 1980):

* Stage I - Involvement limited to a single node or lymphoid tissue in a single organ (excluding bone marrow)

* Stage I - Involvement limited to a single node or lymphoid tissue in a single organ (excluding bone marrow)

* Stage II - Involvement of many lymph nodes in a regional area (+/- tonsils)

* Stage II - Involvement of many lymph nodes in a regional area (+/- tonsils)

* Stage V - Manifestations in the blood and involvement of bone marrow and/or other organ systems (+/-stages I-IV)

* Stage V - Manifestations in the blood and involvement of bone marrow and/or other organ systems (+/-stages I-IV)

Each stage is then subclassifed as a) without systemic signs or b) with systemic signs.

Each stage is then subclassifed as a) without systemic signs or b) with systemic signs. Other lymphomas such as primary hepatic are typically automatically classed as a grade V.

==Treatment==

==Treatment==

'''Surgery'''

'''Surgery'''

:Firstly, a laparotomy is required for many cases of alimentary lymphoma to obtain biopsy material. For solitary masses without systemic disease resection and anastomosis of the intestine is advised (single modality treatment). Local resection in cats has occasionally been curative. Other focal lyphoma may also be resected, however surgery alone may be insufficient for long-term control of the disease and if not all the tumour is able to be resected. Should relapse occur, or if there is systemic progression, chemotherapy will be required (multimodal treatment).

:Firstly, a laparotomy is required for many cases of alimentary lymphoma to obtain biopsy material and in some cases to de-bulk and obstructing mass, though owners should be warned of the high potential of dehiscence post-operatively. For solitary masses without systemic disease, resection and anastomosis of the intestine is advised (single modality treatment). Local resection in cats has occasionally been curative. Other focal lymphoma may also be resected, however as there is typically systemic involvement, chemotherapy will be required (multimodal treatment).

'''Radiotherapy'''

'''Radiotherapy'''

:Lymphoma is highly radiosensitive and in theory radiotherapy should be efficient in treating all forms of lymphoma, however, surrounding tissues often have a low tolerance.

:Lymphoma is highly radiosensitive and in theory radiotherapy should be efficient in treating all forms of lymphoma, however, surrounding tissues often have a low tolerance. The main site for which radiotherapy is used is in nasal lymphoma, though many oncologists combine this with systemic chemotherapy. Half body radiotherapy is currently being trialled in the USA as part of a multi-modal protocol.  

'''Chemotherapy'''

'''Chemotherapy'''

:Combination chemotherapy is the most frequent method of treatment and the most commonly used protocols include:

:Combination chemotherapy is the most frequent method of treatment and the most commonly used protocols include:

:* COP which consists of Cyclophosphamide, Vincristine and Prednisolone. It is frequently used in cats and can be used for induction therapy (8 weeks) as well as a long term maintenance protocol.

:* COP which consists of cyclophosphamide, vincristine and prednisolone. It is frequently used in cats and can be used for induction therapy (8 weeks) as well as a long term maintenance protocol.

:* COAP consists of Cyclophosphamide, Vincristine, Prednisolone and Cytosine arabinoside

:* COAP consists of cyclophosphamide, vincristine, prednisolone and cytosine arabinoside

:* CHOP consists of Cyclophosphamide, Vincristine, Prednisolone and Doxorubicin.  

:* CHOP consists of cyclophosphamide, vincristine, prednisolone and doxorubicin.

:* Prednisolone and chlorambucil can provide good long term palliation in low grade lymphomas, for example feline small cell gastrointestinal lymphoma.  

:Corticosteroids must not be administered prior to initiation of chemotherapy as they can cause resistance to cytotoxics and hence reduce the rate of response and the survival time. The aim is to induce remission and then continue with a maintenance regime, adjusting the dose as required with rescue therapy should relapse occur.  

:Corticosteroids must not be administered prior to initiation of chemotherapy as they can cause resistance to cytotoxics and hence reduce the rate of response and the survival time. The aim is to induce remission and then continue with a maintenance regime, adjusting the dose as required with rescue therapy should relapse occur.  

:Response to treatment can be monitored via reduction in tumour mass and size of lymph nodes. Haematological values should be frequently monitored to assess the effects of the drugs. In particular, animals should be monitored for the presence of [[Azotaemia|azotaemia]], neutropenia/sepsis, [[hypercalcaemia]] and pyrexia.

:Response to treatment can be monitored via reduction in tumour mass or size of lymph nodes. Haematological values should be frequently monitored to assess the effects of the drugs. In particular, animals should be monitored for the presence of [[Azotaemia|azotaemia]], neutropenia/sepsis, [[hypercalcaemia]] and pyrexia.

'''Supportive Therapy'''

'''Supportive Therapy'''

Whilst receiving chemotherapy. patients should receive a high quality, palatable diet to maintain calorific intake. If animals become anorexic they should receive appetite stimulation in cats e.g Cyproheptadine (Periactin) or [[Emetics and Anti-Emetic Drugs|antiemetics]] if vomiting occurs.

Whilst receiving chemotherapy. patients should receive a high quality, palatable diet to maintain calorific intake. If animals become anorexic, the cause should be investigated.

Additionally, [[Principles of Fluid Therapy|fluid therapy]], laxatives and [[Systemic Analgesia|analgesia]] may be required.

 

Unfortunately it is unusual for animals with lymphoma to be cured, and whilst the disease goes into remission in most patients treated with multi-modal chemotherapy, typically they will relapse after a period of weeks to months. At this time, rescue chemotherapy can be performed but often does not provide a long second remission period.

===Horses===

===Horses===

==Prognosis==

==Prognosis==

===Cats and Dogs===

===Cats and Dogs===

The mean survival times for dogs and cats without therapy is 6-8 weeks. For those receiving corticosteroids alone is 3 months.

The mean survival times for dogs and cats without therapy is 6-8 weeks. For those receiving corticosteroids alone it is thought to be around 3 months.

If chemotherapy is administered then the mean survival time increases to 6-9 months.

If chemotherapy is administered then the mean survival time increases to 6-12 months for canine multicentric lymphoma depending on the protocol used and a huge variety of other factors - the median survival of other disease sites and species is less well documented. Documented poor prognostic indicators in the dog include T cell immunophenotype, cranial mediastinal involvement, hypercalcemia, bone marrow involvement and being ill at diagnosis (substage b).  

Local canine lymphoma responds better to chemotherapy than the diffuse form of disease.  

Local canine lymphoma responds better to chemotherapy than the diffuse form of disease.  

Immunophenotype (T cell versus B cell lymphoma) does not appear to be associated with prognosis in cats as it can be in dogs. Factors indicating a better prognosis (overall survival) in '''cats''' include: '''an early presentation, a complete initial response to treatment and a clinically well patient''' (‘substage a’ disease).

Immunophenotype (T cell versus B cell lymphoma) does not appear to be associated with prognosis in cats as it can be in dogs. Factors indicating a better prognosis (overall survival) in '''cats''' include: '''an early presentation, a complete initial response to treatment and a clinically well patient''' (‘substage a’ disease).

{{Learning

{{Learning

|flashcards = [[Feline Medicine Q&A 12]]<br>[[Feline Medicine Q&A 19]]<br>[[Cytology Q&A 03]]<br>[[Cytology Q&A 10]]<br>[[Equine Internal Medicine Q&A 18]]

|flashcards = [[Feline Medicine Q&A 12]]<br>[[Feline Medicine Q&A 19]]<br>[[Cytology Q&A 03]]<br>[[Cytology Q&A 10]]<br>[[Equine Internal Medicine Q&A 18]]

|literature search = [http://www.cabdirect.org/search.html?q=title%3A%28lymphoma%29+AND++od%3A%28dogs%29 Lymphoma in dogs publications]

|literature search = [http://www.cabdirect.org/search.html?q=title%3A%28lymphoma%29+AND++od%3A%28dogs%29 Lymphoma in dogs publications]

{{review}}

{{review}}

[[Category:Stomach_and_Abomasum_-_Proliferative_Pathology]][[Category:Lymphoreticular and Haemopoietic Diseases]]

[[Category:Stomach_and_Abomasum_-_Proliferative_Pathology]][[Category:Lymphoreticular and Haemopoietic Diseases]]

[[Category:Neoplasia]][[Category:Intestines_-_Proliferative_Pathology]][[Category:Tongue_-_Pathology]]

[[Category:Neoplasia]][[Category:Intestines_-_Proliferative_Pathology]][[Category:Tongue_-_Pathology]]