Mast Cell Tumours
Learn what the condition is, how it may be detected early, how it is treated or managed, and which breeds or species are linked to it.
Condition snapshot
A concise guide to the condition’s pattern, detection, management and urgency.
This snapshot is a general guide, not a diagnosis or treatment plan. New, severe or worsening signs require veterinary assessment.
About the condition
Mast cell tumours arise from mast cells, immune cells involved in allergic and inflammatory responses. In cats, mast cell tumours most commonly affect the skin or spleen, although intestinal and other forms occur. Their biological behaviour differs from mast cell tumours in dogs and also varies according to the feline tumour site.
Cutaneous mast cell tumours often appear as small, firm, raised or hairless nodules on the head, neck or body. Some are itchy or intermittently swollen because mast cells release histamine and other inflammatory substances. Many skin tumours in cats behave relatively benignly and can be cured by complete surgical removal.
Visceral mast cell disease can be more serious. Splenic disease may cause lethargy, weight loss, vomiting, anaemia or enlargement of the spleen. Intestinal mast cell tumours can cause vomiting, diarrhoea, poor appetite and weight loss and may be more aggressive.
A lump cannot be identified reliably by touch alone. Because many feline mast cell tumours are treatable, early sampling is worthwhile rather than waiting for a small nodule to grow.
Feline mast cell disease is a good example of why a diagnosis should not be borrowed directly from canine expectations. A small skin mast cell tumour in a cat often behaves very differently from an aggressive canine tumour, while an intestinal feline mast cell tumour can be considerably more serious. Site-specific interpretation is essential.
A persistent, growing or changing skin lump cannot be classified reliably by appearance because feline mast cell tumours vary widely in colour and texture. Visceral mast cell disease may cause weight loss, vomiting, diarrhoea, anaemia or splenic enlargement without producing a visible skin mass. Cutaneous disease may be visible during grooming, whereas visceral mast cell disease can progress without any external lump.
Screening & Early Detection
Fine-needle aspiration is quick and often provides a useful first answer for mast cell tumours. Multiple nodules or recurrent lesions deserve broader assessment.
If mast cells are identified, the veterinarian considers tumour location, number and the cat’s general health. Biopsy may be recommended to confirm the type and evaluate surgical margins. Abdominal palpation, ultrasound and blood tests are appropriate when splenic, intestinal or disseminated disease is possible.
Ultrasound can identify internal masses and guide sampling.
There is no routine screening blood test for healthy cats. Cats with previous mast cell tumours should have new nodules examined promptly because a second lesion is not automatically harmless or identical to the first.
Diagnosis begins with sampling the mass. Fine-needle aspiration often reveals characteristic mast cells, while biopsy provides more information about tumour type and margins. Blood tests and abdominal imaging are used when internal disease or spread is suspected. Prognosis ranges from excellent for many solitary skin tumours to more guarded for some intestinal or disseminated forms, so tumour location and staging are essential parts of the diagnosis.
Treatment & Management
A solitary cutaneous mast cell tumour is commonly treated by surgical excision. Many feline skin tumours have a favourable prognosis after complete removal, and wide radical margins are not always necessary to the same extent as in canine mast cell disease. Histopathology confirms the diagnosis and assesses margins.
Splenic mast cell disease may be treated with splenectomy, which can provide substantial survival time in selected cats even when mast cells are detected elsewhere. Intestinal or disseminated disease is more complex and may require chemotherapy, targeted medication or other oncology treatment.
Antihistamines or supportive medication may be used when mast-cell mediator release causes gastrointestinal signs or swelling, but these drugs do not eliminate the tumour. Treatment choice is based on location, stage and tumour behaviour.
Follow-up includes checking for new skin nodules and monitoring for recurrence or systemic signs. Cats generally adapt well after splenectomy when it is indicated. Prognosis is excellent for many localised cutaneous tumours, more variable for splenic disease and more guarded for aggressive intestinal forms. Veterinary oncology input is useful when disease is internal, recurrent or widespread.
Breeds or species affected
Abyssinian
Open cat breed description, care requirements and conditions
American Bobtail
Open cat breed description, care requirements and conditions
American Curl
Open cat breed description, care requirements and conditions
American Shorthair
Open cat breed description, care requirements and conditions
American Wirehair
Open cat breed description, care requirements and conditions
Arabian Mau
Open cat breed description, care requirements and conditions
Aegean
Open cat breed description, care requirements and conditions
Australian Mist
Open cat breed description, care requirements and conditions
Balinese
Open cat breed description, care requirements and conditions
Bengal
Open cat breed description, care requirements and conditions
Birman
Open cat breed description, care requirements and conditions
Bombay
Open cat breed description, care requirements and conditions
British Longhair
Open cat breed description, care requirements and conditions
British Shorthair
Open cat breed description, care requirements and conditions
Burmese
Open cat breed description, care requirements and conditions
Burmilla
Open cat breed description, care requirements and conditions
Chartreux
Open cat breed description, care requirements and conditions
Chausie
Open cat breed description, care requirements and conditions
Colorpoint Shorthair
Open cat breed description, care requirements and conditions
Cornish Rex
Open cat breed description, care requirements and conditions
Cymric
Open cat breed description, care requirements and conditions
Devon Rex
Open cat breed description, care requirements and conditions
Domestic Longhair
Open cat breed description, care requirements and conditions
Domestic Medium Hair
Open cat breed description, care requirements and conditions
Domestic Shorthair
Open cat breed description, care requirements and conditions
Donskoy
Open cat breed description, care requirements and conditions
Egyptian Mau
Open cat breed description, care requirements and conditions
European Shorthair
Open cat breed description, care requirements and conditions
Exotic Shorthair
Open cat breed description, care requirements and conditions
Havana Brown
Open cat breed description, care requirements and conditions
Highlander
Open cat breed description, care requirements and conditions
Himalayan
Open cat breed description, care requirements and conditions
Japanese Bobtail
Open cat breed description, care requirements and conditions
Khao Manee
Open cat breed description, care requirements and conditions
Korat
Open cat breed description, care requirements and conditions
Kurilian Bobtail
Open cat breed description, care requirements and conditions
LaPerm
Open cat breed description, care requirements and conditions
Lykoi
Open cat breed description, care requirements and conditions
Maine Coon
Open cat breed description, care requirements and conditions
Manx
Open cat breed description, care requirements and conditions
Minuet
Open cat breed description, care requirements and conditions
Minskin
Open cat breed description, care requirements and conditions
Munchkin
Open cat breed description, care requirements and conditions
Nebelung
Open cat breed description, care requirements and conditions
Norwegian Forest Cat
Open cat breed description, care requirements and conditions
Ocicat
Open cat breed description, care requirements and conditions
Oriental Longhair
Open cat breed description, care requirements and conditions
Oriental Shorthair
Open cat breed description, care requirements and conditions
Persian
Open cat breed description, care requirements and conditions
Peterbald
Open cat breed description, care requirements and conditions
Pixiebob
Open cat breed description, care requirements and conditions
RagaMuffin
Open cat breed description, care requirements and conditions
Ragdoll
Open cat breed description, care requirements and conditions
Russian Blue
Open cat breed description, care requirements and conditions
Savannah
Open cat breed description, care requirements and conditions
Scottish Fold
Open cat breed description, care requirements and conditions
Scottish Straight
Open cat breed description, care requirements and conditions
Selkirk Rex
Open cat breed description, care requirements and conditions
Siamese
Open cat breed description, care requirements and conditions
Siberian
Open cat breed description, care requirements and conditions
Singapura
Open cat breed description, care requirements and conditions
Snowshoe
Open cat breed description, care requirements and conditions
Somali
Open cat breed description, care requirements and conditions
Sphynx
Open cat breed description, care requirements and conditions
Thai
Open cat breed description, care requirements and conditions
Tonkinese
Open cat breed description, care requirements and conditions
Toybob
Open cat breed description, care requirements and conditions
Toyger
Open cat breed description, care requirements and conditions
Turkish Angora
Open cat breed description, care requirements and conditions
Turkish Van
Open cat breed description, care requirements and conditions
Bambino
Open cat breed description, care requirements and conditions
Cheetoh
Open cat breed description, care requirements and conditions
Dwelf
Open cat breed description, care requirements and conditions
Elf Cat
Open cat breed description, care requirements and conditions
Genetta
Open cat breed description, care requirements and conditions
Kinkalow
Open cat breed description, care requirements and conditions
Lambkin
Open cat breed description, care requirements and conditions
Serengeti
Open cat breed description, care requirements and conditions
Skookum
Open cat breed description, care requirements and conditions
Ukrainian Levkoy
Open cat breed description, care requirements and conditions