This blog has two Vet Case Studies.
1. A sneezing cat has a swollen right facial swelling.
2. A cat has left ear cancer.
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VET CASE STUDY 1.
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VET CASE STUDY 2.
Squamous cell carcinoma
(SCC) is a type of skin cancer. It appears in white or light-coloured
fur of the cat's ear tips, nose and eyelids.
Caused by chronic
exposure to ultraviolet radiation from the sun.
Presented as
scabs or sores that progress to ulcerated red and weepy areas.
Recurrence can recur, especially
if surgical margins are not clear, making follow-up care
essential.
Resection
margins free of tumor" means that when a surgeon removes a
tumor, the tissue surrounding the tumor (the margins) shows no
evidence of cancer cells upon microscopic examination by a
pathologist. This is also referred to as a "negative"
or "clear" margin. It indicates that all visible
cancerous tissue has likely been removed during surgery.
Resection Margins:
These are the edges of the tissue that are removed along with the tumor during surgery.
Pathological Examination:
The removed tissue is sent to a pathologist, who examines it under a microscope to determine if cancer cells are present at the margins.
Negative Margin (Free of Tumor):
If no cancer cells are found at the edges of the tissue, the margin is considered negative, or free of tumor. This suggests that the entire tumor has been removed.
Positive Margin (Involved Margin):
If cancer cells are found at the edges of the tissue, the margin is considered positive or involved. This indicates that some cancer cells may remain in the patient, and further treatment (like additional surgery or radiation) may be needed.
Close Margin:
A close margin is a situation where cancer cells are found close to the edge of the removed tissue, but not actually touching it. The distance considered "close" can vary, but it is often defined as less than 1-2 mm, according to some medical guidelines.
Importance of Clear Margins:
Achieving clear resection margins is a key goal in cancer surgery, as it is associated with a lower risk of cancer recurrence.
Variations in Definition:
While a clear margin is generally defined as the absence of cancer cells at the edge of the removed tissue, the specific distance considered a clear margin can vary depending on the type of cancer and the surgical procedure.
UPDATE:
https://2010vets.blogspot.com/2025/06/4153-squamous-cell-carcinoma-in-cat.html
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- Primarily caused by chronic exposure to ultraviolet (UV) light, especially UVB radiation, from the sun.
- Most commonly found on sparsely haired, non-pigmented areas like the ear tips, nose, and eyelids.
- Begins as small scabs or sores, which can then develop into ulcerated, red, and weepy areas.
- SCC is locally invasive, meaning it can spread to surrounding tissue, but it is generally slow to metastasize to distant parts of the body.
- White cats, cats with little or no pigment, and cats with sparse hair are at higher risk.
- Surgery is often the preferred treatment for localized tumors, and other options include cryosurgery (freezing), radiation therapy, and in some cases, chemotherapy.
- Protecting cats from excessive sun exposure by using pet-safe sunscreen or keeping them indoors during peak sunlight hours is crucial.
- SCC in cats can affect the ear flap (pinna) and the ear canal.
- Ear canal SCC can be particularly problematic, as it can spread to the middle and inner ear, potentially impacting hearing and causing neurological issues.
- Symptoms of ear canal SCC may include inflamed, itchy, and painful ears, smelly discharge, head shaking, and ear scratching.
Auricular Squamous Cell Carcinoma in Cats
Cats can be afflicted with several types of skin tumors, even on their ears. One type of tumor that can affect the ears is a squamous cell carcinoma. A squamous cell carcinoma (SCC) can be described as a malignant and particularly invasive tumor that takes hold in the scale like cells of the epithelium – the tissue that covers the body or lines the cavities of the body. These scale-like tissue cells are called the squamous.
Carcinoma is, by definition, an especially malignant and persistent form of cancer, often returning after is has been excised from the body and metastasizing to other organs and locations on the body.
An auricular (relating to the ear) squamous cell carcinoma may be caused by excess sun exposure. It is more common in white cats and in cats that have white ears. This type of tumor starts out as red, crusty looking areas on the tips of the ears. The sores, or ulcers, may seem to come and go and will slowly get bigger with time. There may be ulcers on the face as well. This type of cancer can be treated successfully if it is caught early.
Symptoms and Types
- Red, crusted sores on the edges of the ears
- Redness may come and go
- Bleeding ulcers on the ears
- Ulcers on the ear that slowly get bigger
- As sores get larger, ear tips may disappear, ear may become malformed
- Sometimes, sores on the face
Causes
- Excessive exposure to the sun over a long period
Diagnosis
You will need to provide a thorough history of your cat's health leading up to the onset of symptoms. Be sure to describe any sores that have been apparent on other parts of the body, even if you suspect they were caused by injuries resulting from outdoor activity, or from scratching at the skin.
During the examination, your veterinarian will look carefully for other sores or tumors on your cat's body. The lymph nodes will be carefully felt to determine if they are enlarged, an indication that the body is reacting to an infection or invasion. A sample of lymph fluid may be taken to test for cancerous cells.
Your veterinarian will order complete blood count and biochemistry profile to make sure your cat's other organs are working normally and to determine whether the white blood cell count is higher than normal; again, an indication that the body is fighting an invasive disease or infection.
A biopsy will be taken of the ulcerated tissue on your cat's ear so that your doctor can diagnose the specific type of growth it is, whether carcinoma or a benign mass of tissue. This is necessary for differentiating the ulcers from any other condition that could be causing the same symptoms.
X-rays images of your cat's chest and skull will allow your veterinarian to visually inspect the lungs for signs of any abnormalities, especially tumors, and to make sure that the carcinoma has not spread into the bones.
Treatment
Treatment will depend on how many ulcers your cat has on its ears and how large the ulcers are. If there is only one small ulcer, it may be removed by cryosurgery, a freezing technique. If the ulcer is larger, or if there are several ulcers, it/they will be treated with surgery. During surgery, most or all of the upright part (pinna) of your cat's ear will be removed. In some cases, the ear canal may also need to be removed. Most cats recover well from this surgery, even if the ear canal needs to be removed.
If surgery is not a practical option, chemotherapy may be used to kill the cancerous cells. However, chemotherapy is not usually as effective as surgery. In some cases, your veterinarian may recommend a veterinary cancer specialist so that you can determine if there are other viable treatment options.
Living and Management
Once your cat has recovered from surgery, it should be able to lead a normal life. Your cat may look different, but it will adjust to its changed body. You will need to monitor your cat closely to make sure it does not develop new sores on its face or head. Try to limit the amount of time your cat spends out in the sun. If you must let your cat out during the daytime, you will need to apply sunscreen to areas of the body that have a thin hair coat. If your cat tends to spend a lot of time on the window sill, you might place a shade or reflector over the glass to block ultraviolet (UV) rays from reaching your cat.
As with any cancer, it is recommended that you take your cat for regular progress check with your veterinarian.
Prevention
Limit the amount of time your cat spends in the sun, especially if it is white cat, or if it has a lighter hair coat. When your cat does go out in the sun, apply sunscreen to its ears and nose.
- SCC is strongly associated with UV damage from the sun.
- Initially, it may look like a non-healing scab or crusty area on the ear, nose, or eyelid.
- If untreated, the lesion can progress to an ulcerated area with potential for secondary bacterial infections.
- SCC commonly affects the ear tips and ear canal, but can also be found on the nose and eyelids.
- White cats, or those with white patches, are more susceptible due to their lack of protective pigmentation.
- While SCC is locally invasive, it tends to spread to other parts of the body more slowly than other cancers.
- A fine needle aspiration (FNA) or biopsy can help confirm the diagnosis.
- Treatment options include surgery, cryotherapy (freezing), or radiation therapy, depending on the stage and location of the cancer.
- Regular skin checks and prompt veterinary attention for any suspicious lesions are vital for successful treatment.
- Limiting sun exposure and using pet-safe sunscreen on vulnerable areas can help prevent SCC.
- In some cases, SCC can affect multiple locations, and treatment may involve a combination of approaches.
- While generally slow to spread, SCC can be aggressive if left untreated, potentially affecting the ear canal and deeper structures.
- SCC can recur, especially if surgical margins are not clear, making follow-up care essential.
- The report includes a detailed description of the tissue sample, noting its size, color, and any other macroscopic features.
- This is the core of the report, where the pathologist describes the tissue's cellular structure, including any abnormalities, such as inflammation, infection, or cancerous changes.
- Based on the microscopic findings, the pathologist provides a diagnosis, which may include the type of disease, its stage, and grade.
- For some conditions, particularly cancer, the report may include a prognosis, which is an assessment of the likely outcome of the disease.
- The report may also include comments on the tissue margins (the edges of the tissue sample), special stains used, and recommendations for further testing.
- Biopsy Reports: These reports are based on tissue samples obtained during a biopsy, which is a procedure to collect a small piece of tissue for examination.
- Surgical Resection Reports: These reports cover all the tissue removed during a surgical procedure.
- Histopathology is a critical tool for diagnosing a wide range of diseases, allowing doctors to accurately identify the underlying cause of a patient's symptoms.
- The information in a histopathology report is essential for developing appropriate treatment plans, including surgery, radiation therapy, chemotherapy, or other therapies.
- Histopathology helps doctors understand the likely course of a disease and predict the patient's response to treatment.
- Histopathology can be used to monitor the effectiveness of treatment and detect any recurrence of the disease.
- Histopathology reports can be complex, so it's best to discuss the report with your doctor or a pathologist.
- Your doctor can explain the findings in detail, answer your questions, and help you understand the implications of the report.
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