猫のリンパ腫によく見られる病型

執筆者 TCMVET | 2024年9月4日 | 猫の癌と腫瘍

Feline lymphoma is one of the most common cancers found in cats, affecting the lymphatic system, which plays a crucial role in the body’s immune response. This type of cancer can manifest in several different areas of the body, each presenting its own set of symptoms and requiring specific treatment approaches. In this article, we will explore the most common forms of feline lymphoma, their symptoms, and how to detect and treat them.

1. Alimentary Lymphoma

Alimentary lymphoma is the most common form of feline lymphoma and primarily affects the gastrointestinal (GI) tract. It often occurs in middle-aged to older cats, typically between the ages of 9 and 13 years old. This form of lymphoma usually involves the intestines, but it can also spread to the liver, pancreas, and surrounding lymph nodes.

Symptoms of alimentary lymphoma include:

• 慢性的な下痢または便秘
• 嘔吐
• 体重減少
• Lack of appetite (anorexia)
• Black, tarry stools (indicative of bleeding in the GI tract)

Alimentary lymphoma is the least likely form to be associated with feline leukemia virus (FeLV), but it is still crucial to seek early veterinary care if you notice these symptoms.

2. Mediastinal Lymphoma

Mediastinal lymphoma occurs in the chest cavity, specifically between the lungs, and typically involves the thymus gland and nearby lymph nodes. This form of lymphoma is often associated with feline leukemia virus (FeLV), particularly in younger cats.

Symptoms of mediastinal lymphoma include:

• 呼吸困難（呼吸困難）
• Open-mouth breathing
• 持続的な咳
• 食欲不振
• Noticeable weight loss

Cats with mediastinal lymphoma may also develop pleural effusion, a buildup of fluid around the lungs that makes breathing more difficult. Early detection and diagnosis are critical, especially in cats already diagnosed with FeLV.

3. Multicentric Lymphoma

Multicentric lymphoma affects multiple lymph nodes and organs throughout the body. It is often associated with feline leukemia virus and can involve various tissues, including the spleen, liver, and bone marrow.

Symptoms of multicentric lymphoma include:

• Swollen lymph nodes (commonly under the jaw, in the armpits, or groin area)
• Extreme lethargy
• Significant weight loss
• Lack of appetite

This form of lymphoma is one of the most aggressive types and can rapidly affect multiple organ systems. Swollen lymph nodes are a key indicator, and early diagnosis is essential for effective treatment.

4. Renal Lymphoma

Renal lymphoma specifically affects the kidneys, which can have a significant impact on your cat’s overall health and ability to function. This type of lymphoma is also aggressive and often spreads to the central nervous system if left untreated.

Symptoms of renal lymphoma include:

• Increased thirst (polydipsia) and frequent urination (polyuria)
• 嘔吐
• 弱さまたは無気力
• 食欲不振と体重減少
• Abdominal discomfort or swelling

Renal lymphoma can lead to kidney failure if not treated promptly. If you notice these signs, it is crucial to consult your veterinarian immediately.

5. Nasal Lymphoma

Nasal lymphoma affects the nasal passages and surrounding areas of the head. While less common than other forms of feline lymphoma, nasal lymphoma can cause severe discomfort for your cat due to its effect on breathing and the structure of the face.

Symptoms of nasal lymphoma include:

• Persistent sneezing
• Nasal discharge (clear, yellow, or blood-tinged)
• Difficulty breathing through the nose
• 顔の腫れや変形
• Loud breathing or snoring

Nasal lymphoma can sometimes be mistaken for respiratory infections, so if these symptoms persist, veterinary evaluation is necessary.

6. Solitary Lymphoma

Solitary lymphoma refers to lymphoma that occurs in one isolated area of the body. This can include the liver, spleen, skin, or any other single organ. Symptoms of solitary lymphoma vary depending on the location of the tumor.

例えば：

• Lymphoma in the skin: Visible lumps, ulcers, or skin lesions
• Lymphoma in the liver: Jaundice, weight loss, vomiting
• Lymphoma in the central nervous system: Seizures, disorientation, or other neurological symptoms

Solitary lymphoma can be easier to treat in some cases, especially if the tumor is confined to a single area and detected early.

Diagnosing and Treating Feline Lymphoma

Diagnosing feline lymphoma typically involves a combination of diagnostic tests, including blood work, X-rays, ultrasounds, and tissue biopsies. Once a diagnosis is confirmed, treatment options usually include chemotherapy, radiation therapy, or surgery, depending on the type and stage of the lymphoma.

The prognosis for feline lymphoma varies based on several factors, including the location of the cancer, how early it is detected, and the cat’s overall health. While lymphoma is serious, many cats respond well to treatment and can achieve remission, improving their quality of life.

Feline lymphoma is a complex and multifaceted disease that can manifest in different parts of your cat’s body. Understanding the common forms of lymphoma, such as alimentary, mediastinal, multicentric, renal, nasal, and solitary lymphoma, can help you recognize early warning signs and seek prompt veterinary care. Early diagnosis and treatment are key to improving your cat’s prognosis and ensuring they receive the best possible care.