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Possible mammary tumours include:
Possible mammary tumours include:
:'''Benign''': Adenoma/fibroadenoma
:'''Benign''': [[adenoma]]/fibroadenoma, benign mesenchymal tumour, benign mixed tumour
:'''Malignant''': [[carcinoma]] (solid, tubular, papillary, inflammatory), [[sarcoma]], carcinosarcoma, [[adenocarcinoma]]
==Clinical Presentation==
==Clinical presentation==
The animal will present with a history of the owner noticing a '''lump''', or it may be discovered during routing physical examination. It is rare for the animal to present with signs referable to metastases such as coughing or lameness.
The animal will present with a history of the owner noticing a '''lump''', or it may be discovered during routing physical examination. It is rare for the animal to present with signs referable to metastases such as coughing or lameness.
==Diagnosis==
==Diagnosis==
Mammary neoplasms cannot be diagnosed visually.
Mammary neoplasms cannot be diagnosed visually. The aim is to obtain a diagnosis and to stage the disease using the '''TNM system''':
:<u>Tumour size</u>: T1 <3cm, T2 3-5cm, T3 >5cm
:<u>Regional lymph node</u>: N0 no metastasis, N1 metastasis
:<u>Distant metastasis</u>: M0 not present, M1 present
'''Haematology and biochemistry''' should be performed to make sure geriatric patients are safe to anaesthetise.
'''Radiography''' of the thorax and abdomen to check for distant metastases is recommended.
'''Radiography''' of the thorax and abdomen to check for distant metastases
'''Abdominal ultrasound''' to check the sublumbar and inguinal lymph nodes is also useful.
'''Fine needle aspiration and cytological analysis''' of the mass is an essential tool: it may reveal cells with criteria for malignancy, with distinct nucleoli, high nuclear-cytoplasmic ratio and moderate anisocytosis and anisokaryosis.
'''Fine needle aspiration and cytological analysis''' of the mass is an essential tool: it may reveal cells with criteria for malignancy, with distinct nucleoli, high nuclear-cytoplasmic ratio and moderate anisocytosis and anisokaryosis.
'''Immunohistochemistry''' can be performed to determine the presence of hormone receptors in the tumour, but this is an expensive test which does not really alter the treatment plan.
'''Immunohistochemistry''' can be performed to determine the presence of hormone receptors in the tumour, but this is an expensive test which does not really alter the treatment plan.
Other diseases which may '''mimic mammary masses''' and which should be ruled out include:
Other diseases which may '''mimic mammary masses''' and which should be ruled out include:
==Prognosis==
==Prognosis==
In '''dogs''', prognostic factors include:
In '''dogs''', prognostic factors include:
:'''Tumour size''': <3cm 30% recurrence, >3cm 85% recurrence
'''Tumour size''': <3cm 30% recurrence, >3cm 85% recurrence
:'''Histologic type''': sarcomas are worse than carcinomas or mixed types
:'''Grade/differentiation''': 90% mortality at 2 years if the cells are poorly differentiated, 24% mortality at 2 years if the cells are well differentiated.
'''Histologic type''': sarcomas are worse than carcinomas or mixed types
:'''Lymph node involvement''': if present, there is 80% recurrence.
:'''Distant metastases''' have a poorer prognosis
'''Grade/differentiation''': 90% mortality at 2 years if the cells are poorly differentiated, 24% mortality at 2 years if the cells are well differentiated.
:'''Presence of progesterone/oestrogen receptors''' holds a better prognosis.
'''Lymph node involvement''': if present, there is 80% recurrence.
'''Distant metastases''' have a poorer prognosis
'''Presence of progesterone/oestrogen receptors''' holds a better prognosis.
There is no evidence that site or number of tumours is a prognostic indicator.
There is no evidence that site or number of tumours is a prognostic indicator.
'''Inflammatory carcinomas''' have a grave prognosis with <4 weeks survival time. '''Malignant tumours''' incompletely excised hold a 75% mortality within the year. Dogs with malignant tumours completely excised and with no evidence of metastases are expected to live 1-2 years. Complete excision of '''benign tumours''' is curative.
'''Inflammatory carcinomas''' have a grave prognosis with <4 weeks survival time. '''Malignant tumours''' incompletely excised hold a 75% mortality within the year. Dogs with malignant tumours completely excised and with no evidence of metastases are expected to live 1-2 years. Complete excision of '''benign tumours''' is curative.
In '''cats''', prognostic factors include:
In '''cats''', prognostic factors include:
:'''Tumour size''': >3cm medial survival time <6 months, <2cm median survival time 3 years.
'''Tumour size''': >3cm medial survival time <6 months, <2cm median survival time 3 years.
:'''Extent of surgery''': there is 66% recurrence if local surgery rather than radical mastectomy is performed
:'''Histologic grading''': well differentiated tumours with no evidence of lymphatic invasion have a better prognosis.
'''Extent of surgery''': there is 66% recurrence if local surgery rather than radical mastectomy is performed
'''Histologic grading''': well differentiated tumours with no evidence of lymphatic invasion have a better prognosis.
The overall median survival time is <1 year and the disease hold a '''poor prognosis overall in cats'''.
The overall median survival time is <1 year and the disease hold a '''poor prognosis overall in cats'''.
In cats the relative risk if spayed '''before 1 year''' is 0.6% compared to intact cats.
In cats the relative risk if spayed '''before 1 year''' is 0.6% compared to intact cats.
<big><b>Also see [[Mammary Neoplasia - Rat]]</b></big>
==References==
==References==
{{review}}
[[Category:Expert Review - Small Animal]]
[[Category:Neoplasia]]
[[Category:Neoplasia]]
[[Category:Mammary Gland - Pathology]]
[[Category:Mammary Gland - Pathology]]
[[Category:To Do - Reproductive]]
[[Category:Reproductive Diseases - Dog]]
[[Category:Reproductive Diseases - Cat]]
[[Category:Dermatological Diseases - Cat]]
[[Category:Dermatological Diseases - Dog]]