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Also know as: '''''Lymphosarcoma'''''
==Introduction==
==Introduction==
[[Image:tonguelymphoma.gif|right|thumb|125px|<small><center>Tongue Lymphoma - a recognised entity (Courtesy of Alun Williams (RVC))</center></small>]]
[[Image:tonguelymphoma.gif|right|thumb|125px|<small><center>Tongue Lymphoma - a recognised entity (Courtesy of Alun Williams (RVC))</center></small>]]
Lymphoma is caused by malignant clonal expansion of lymphoid cells and most commonly arises from lymphoid tissues including the [[Bone Marrow|bone marrow]], [[Thymus - Anatomy & Physiology|thymus]], [[Lymph Nodes - Anatomy & Physiology|lymph nodes]] and [[Spleen - Anatomy & Physiology|spleen]]. Lymphoma is documented to be the most common haematopoietic [[Neoplasia - Pathology|neoplasm]] in dogs.
Lymphoma is caused by malignant clonal expansion of lymphoid cells and most commonly arises from lymphoid tissues including the [[Bone Marrow|bone marrow]], [[Thymus - Anatomy & Physiology|thymus]], [[Lymph Nodes - Anatomy & Physiology|lymph nodes]] and [[Spleen - Anatomy & Physiology|spleen]]. Lymphoma is documented to be the most common haematopoietic [[Neoplasia - Pathology|neoplasm]] in dogs.
In the '''dog''', multicentric lymphoma is most common representing 80% of cases. Alimentary, cutaneous, mediastinal and extranodal sites are less common. Additionally the majority of lymphoma cases in dogs are of the B-cell immunophenotype.
===Dog===
In the dog, '''multicentric''' lymphoma is most common representing 80% of cases. Alimentary, cutaneous, mediastinal and extranodal sites are less common. Additionally the majority of lymphoma cases in dogs are of the B-cell immunophenotype.
In '''cats''' following the introduction of widespread [[Feline Leukaemia Virus|FeLV]] testing and [[vaccines|vaccination]] the most common type of lymphoma affecting cats is alimentary when previously it had been mediastinal and multicentric forms.
===Cat===
In cats following the introduction of widespread [[Feline Leukaemia Virus|FeLV]] testing and [[vaccines|vaccination]] the most common type of lymphoma affecting cats is '''alimentary''' when previously it had been mediastinal and multicentric forms.
Only 10% of lymphoma cases in cats are now associated with FeLV.
Only 10% of lymphoma cases in cats are now associated with FeLV.
===Horse===
In horses, lymphoma is the most common haemopoietic neoplasm. It has been characterised into four main forms: '''alimentary, cutaneous, mediastinal and multicentric'''.
==Signalment==
==Signalment==
===Dog===
Affected dogs have a wide age range, most are middle-aged however young
animals can be affected. There may also be a male predilection.
===Cat===
The median age of affected cats is 9-10 years and oriental [[Feline Breeds - WikiNormals|cat breeds]] may be predisposed.
The median age of affected cats is 9-10 years and oriental [[Feline Breeds - WikiNormals|cat breeds]] may be predisposed.
===Horse===
There are no sex, age or breed predilections.
==Clinical Signs==
==Clinical Signs==
===Dogs===
===Dogs===
'''Multicentric Lymphoma'''
'''Multicentric Lymphoma'''
:The most common presenting sign in dogs is a lymphadenopathy, with only 10-20% of dogs presenting clinically unwell. Dogs that do present with clinical signs may be anorexic, lethargic and have lost weight.
The most common presenting sign in dogs is a lymphadenopathy, with only 10-20% of dogs presenting clinically unwell. Dogs that do present with clinical signs may be anorexic, lethargic and have lost weight.
For other types of lymphoma affecting dogs the clinical signs will demonstrate the anatomical site affected.
For other types of lymphoma affecting dogs the clinical signs will demonstrate the anatomical site affected.
===Cats===
===Cats===
In contrast to dogs, cats are more likely to present unwell. Again the clinical signs will depend on the anatomical location affected.
In contrast to dogs, cats are more likely to present unwell. Again the clinical signs will depend on the anatomical location affected.
'''Alimentary''' cats will present with vomiting, diarrhoea, weight loss and anorexia.
'''Alimentary''' cats will present with vomiting, diarrhoea, weight loss and anorexia.
'''Mediastinal''' cats will present with signs of compression of structures in the cranial thorax. These include dyspnoea, coughing and tachypnoea due to compression of the trachea. Weight loss and regurgitation may also occur secondary to compression of the oesophagus. On auscultation lung sounds are displaced caudally and lung sounds are decreased ventrally. There may be a loss of compressability ('rib spring') over the cranial thorax. There may be pleural effusion present. Differential diagnoses for a cranial mediastinal mass are: thymoma, thyroid adenocarcinoma, a mediastinal abscess, or a branchial cyst.
'''Mediastinal''' cats will present with signs of compression of structures in the cranial thorax. These include dyspnoea, coughing and tachypnoea due to compression of the trachea. Weight loss and regurgitation may also occur secondary to compression of the oesophagus. On auscultation lung sounds are displaced caudally and lung sounds are decreased ventrally. There may be a loss of compressibility ('rib spring') over the cranial thorax. There may be pleural effusion present. Differential diagnoses for a cranial mediastinal mass are: thymoma, thyroid adenocarcinoma, a mediastinal abscess, or a branchial cyst.
'''Renal''' lymphoma also occurs in cats and affected animals will present with signs similar to [[:Category:Renal Failure|renal failure]].
'''Renal''' lymphoma also occurs in cats and affected animals will present with signs similar to [[:Category:Renal Failure|renal failure]].
'''Nasal''' lymphoma cases will present with dyspnoea, nasal discharge, epistaxis, facial pain or distortion and loss of airflow.
'''Nasal''' lymphoma cases will present with dyspnoea, nasal discharge, epistaxis, facial pain or distortion and loss of airflow.
===Horse===
==Physical Examination==
==Physical Examination==
===Cat and Dog===
An abdominal mass may be palpable and bowel loops may feel thickened in alimentary lymphoma. Additionally enlarged mesenteric lymph nodes and enlarged abdominal organs may be palpable. Muffled heart sounds and a non-compressible thoracic region may be found in mediastinal lymphoma.
An abdominal mass may be palpable and bowel loops may feel thickened in alimentary lymphoma. Additionally enlarged mesenteric lymph nodes and enlarged abdominal organs may be palpable. Muffled heart sounds and a non-compressible thoracic region may be found in mediastinal lymphoma.
Petechiae, [[Regenerative and Non-Regenerative Anaemias|anaemia]] and icterus may also be present in any form of lymphoma.
Petechiae, [[Regenerative and Non-Regenerative Anaemias|anaemia]] and [[icterus]] may also be present in any form of lymphoma.
==Laboratory Tests==
===Horse===
===Haematology and Biochemistry===
Haematological analysis should always be performed with suspected lymphoma for staging purposes and for the recording of base-line parameters prior to the initiation of any treatment to assess the severity of any future myelosuppression. Potential abnormalities for those patients with bone marrow involvement may include [[Lymphocytosis|lymphocytosis]], [[Platelet Abnormalities#Thrombocytopaenia|thrombocytopenia]], [[Neutropenia|neutropenia]] and the presence of immature lymphoid precursors.
==Diagnosis==
===Laboratory Tests===
====Blood Tests====
'''Haematological''' analysis should always be performed with suspected lymphoma for staging purposes and for the recording of base-line parameters prior to the initiation of any treatment to assess the severity of any future myelosuppression. Potential abnormalities for those patients with bone marrow involvement may include [[Lymphocytosis|lymphocytosis]], [[Platelet Abnormalities#Thrombocytopaenia|thrombocytopenia]], [[Neutropenia|neutropenia]] and the presence of immature lymphoid precursors.
Affected cats are not usually leukemic.
Affected cats are not usually leukemic.
On biochemistry abnormalities may include hypoproteinaemia, elevated hepatic enzymes and elevated [[Urea|Blood Urea Nitrogen]] /[[Creatinine|creatinine]].
On '''biochemistry''' abnormalities may include hypoproteinaemia, elevated hepatic enzymes and elevated [[Urea|Blood Urea Nitrogen]] /[[Creatinine|creatinine]].
All cats with suspected lymphoma should be tested for '''[[FeLV]]''' and '''[[Feline Immunodeficiency Virus|FIV]]''', usually performed via enzyme-linked immunosorbent assay ([[ELISA testing|ELISA]]) available in general practice in kit form (CITE test). Virus isolation would be required for a definitive result, however this is not only more time consuming but is more expensive. An ELISA is also frequently used for the diagnosis of FIV.
All cats with suspected lymphoma should be tested for [[FeLV]] and [[Feline Immunodeficiency Virus|FIV]], usually performed via enzyme-linked immunosorbent assay ([[ELISA testing|ELISA]]) available in general practice in kit form (CITE test). Virus isolation would be required for a definitive result, however this is not only more time consuming but is more expensive. An ELISA is also frequently used for the diagnosis of FIV.
'''Paraneoplastic Syndrome'''
Dogs may present with hypercalcaemia, this is due to the release of parathyroid hormone - related protein (PTHrp) released by the tumor, which produces these effects by acting like parathyroid hormone. Affected cats are not usually hypercalcaemic.
Dogs may present with [[hypercalcaemia]], this is due to the release of parathyroid hormone - related protein (PTHrp) released by the tumor, which produces these effects by acting like parathyroid hormone. Affected cats are not usually hypercalcaemic.
==Radiography==
===Radiography===
A mass may be visible via plain or contrast abdominal radiography. Both abdominal and thoracic imaging is required in assessing the surrounding structures.
A mass may be visible via plain or contrast abdominal radiography. Both abdominal and thoracic imaging is required in assessing the surrounding structures.
For nasal lymphoma, radiography of the head may reveal: increased soft tissue densities in the nasal cavities and possibly loss of turbinate structure.
For nasal lymphoma, radiography of the head may reveal: increased soft tissue densities in the nasal cavities and possibly loss of turbinate structure.
==Ultrasonography==
===Ultrasonography===
Superior to radiography in assessing infiltration or abnormalities of tissue architecture and assessing the surrounding structures for [[Neoplasia - Pathology#The Process of Metastasis|metastasis]]. Guided aspirates or biopsies may also be taken at this time, including lymph node sampling, to evaluate degree of systemic involvement.
Superior to radiography in assessing infiltration or abnormalities of tissue architecture and assessing the surrounding structures for [[Neoplasia - Pathology#The Process of Metastasis|metastasis]]. Guided aspirates or biopsies may also be taken at this time, including lymph node sampling, to evaluate degree of systemic involvement.
==Cytology/Biopsies==
===Cytology===
For cytology findings in lymphoma cases, please refer to [[Lymphoma - Cytology|this]] article.
For cytology findings in lymphoma cases, please refer to [[Lymphoma - Cytology|this]] article.
===Biopsy===
Nasal lymphoma can be diagnosed by rhinoscopic or blind biopsy using a suction-catheter or grab-forceps technique.
Nasal lymphoma can be diagnosed by rhinoscopic or blind biopsy using a suction-catheter or grab-forceps technique.
'''Bone Marrow Aspirate/Biopsy''' should be taken ideally for all cases as part of the staging procedure.
===Staging===
===Staging===
[[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]]
[[Category:Intestinal Diseases - Cat]][[Category:Gastric Diseases - Cat]][[Category:Lymphoreticular and Haematopoietic Diseases - Cat]]
[[Category:Intestinal Diseases - Cat]][[Category:Gastric Diseases - Cat]][[Category:Lymphoreticular and Haematopoietic Diseases - Cat]]
[[Category:Alimentary Diseases - Horse]]
[[Category:Nasal Cavity - Hyperplastic/Neoplastic Pathology]]
[[Category:Nasal Cavity - Hyperplastic/Neoplastic Pathology]]
[[Category:Respiratory System - Hyperplastic/Neoplastic Pathology]]
[[Category:Respiratory System - Hyperplastic/Neoplastic Pathology]]
[[Category: To Do - Siobhan Brade]]
[[Category: To Do - Siobhan Brade]]
[[Category:To Do - Manson review]]
[[Category:To Do - Manson]]