Panniculitis

 What is this "tumor"?

"Panniculitis is usually visible as a lump but it is an inflammation of the subcutaneous fatty tissue and is not cancerous."

A "tumor" is a lump. Not all are cancerous. Panniculitis is usually visible as a lump but it is an inflammation of the subcutaneous fatty tissue and is not cancerous. Steatitis is a similar inflammation of fatty tissue that may occur in any part of the body.

What do we know about the cause?

Most of these lesions are due to trauma, especially in younger animals and when solitary. Classic sites are on the abdomen of cats. In cats, many are due to bite wounds from fighting. A few, in cats, are idiosyncratic injection reactions. A few are benign fatty tumors (lipomas) that have become inflamed.

Other causes include infections, immunological reactions, steroid treatment, diseases of internal organs such as the pancreas or liver, poor nutrition and diseases that affect the blood supply. These causes are much rarer than simple trauma, so are usually only considered when there are multiple sites or recurrences of panniculitis or steatitis, or other signs of disease.

Is this a common problem?

This is a common problem in cats. 

How will this problem affect my pet?

The most obvious effect is a lump. This may ulcerate, bleed and become secondarily infected or put physical pressure on the surrounding structures.

"Toxic substances may enter the blood stream so your pet may be depressed or have a fever."

As the tissue is often degenerating or dying, toxic substances may enter the blood stream so your pet may be depressed or have a fever.

How is this problem diagnosed? 

Clinically, with the history of rapid appearance and location, your veterinarian may suspect this condition. Accurate diagnosis relies upon microscopic examination of tissue.

Your veterinarian may recommend one or more of various sampling techniques such as fine needle aspiration, punch biopsy and full excision. The sample will be prepared and examined by either cytology or histopathology.. Cytology is the microscopic examination of cell samples obtained by aspiration techniques. This is useful for rapid or preliminary tests but is not as accurate as histopathology, which is done at a specialized laboratory by a veterinary pathologist. Histopathology is the microscopic examination of tissue samples that have been specially prepared and stained. The piece of tissue may be a small part of the mass (biopsy) or the whole lump. Using histopathology, the pathologist can give the most accurate diagnosis, prediction of behavior (prognosis) and assessment of completeness or removal if the entire mass was submitted. Histopathology also rules out other diseases and forms of cancer.

"Distinguishing these and some other types of malignant tumors of vessels and fat can be difficult in cats."

Some forms of cancer resemble this condition clinically. In cats, early removal of abdominal lumps is important because most mammary tumors are malignant and early excision is important in survival time. 'Feline ventral abdominal angiosarcoma' is a malignant tumor with a "bruised" appearance. Distinguishing these and some other types of malignant tumors of vessels and fat can be difficult in cats.

What types of treatment are available?

The most common treatment is surgical removal of the lump. Your pet may also require antibiotic therapy for secondary infection.

Can this problem disappear without treatment?

The inflammatory cells are a reaction to damage or death of the fatty tissue. Whether the inflammation is successful in removing the damaged tissue depends on the size of the lump, number and activity of the cells and how quickly fibrous tissue surrounds and replaces the dead tissue. If this happens, there is often a permanent scar and the blood supply may be lost to any residual dead tissue in the center. This causes further problems unless it is removed surgically.

A few cases of panniculitis are due to primary infection by bacteria or fungi and removal is needed to cure them.

How can I nurse my pet?

Preventing your pet from rubbing, scratching, licking or biting the lump will reduce itching, inflammation, ulceration, infection and bleeding. Any ulcerated area needs to be kept clean.

After surgery, the incision site needs to be kept clean and dry, and your pet should not be allowed to interfere with the site. Report any loss of sutures or significant swelling or bleeding to your veterinarian. If you require additional advice on post-surgical care, please ask.

How will I know if the problem is permanently cured?

"Surgical removal is usually a complete cure."

Surgical removal is usually a complete cure. If the lump is sent for histopathological diagnosis, the diagnosis can be confirmed, the completeness of excision assessed and other diagnoses ruled out.

If the problem in your pet is due to one of the rare non-traumatic causes, further lumps or recurrence in the same site may be rapid (days to weeks). It may be necessary to conduct more tests to find the cause and assess how the underlying problem can be cured.

Are there any risks to my family or other pets?

No, this disease is not transmitted from pet to pet or from pets to people.