🔍 What Is Lymphomatoid Granulomatosis (LYG)?

Lymphomatoid granulomatosis is a rare, aggressive **T-cell lymphoproliferative** disorder. Known for its **angioinvasive** nature, it most commonly affects the **lungs**, but can also involve skin, subcutis, eyes, and other organs :contentReference[oaicite:3]{index=3}.

🐾 Prevalence & Risk

Though canine and human cases are known, in cats LYG is extremely rare—only **3–4 documented cases** exist in veterinary literature :contentReference[oaicite:4]{index=4}. No breed or sex predilection has been identified, but all reported cats were middle-aged (~7–9 years).

⚠️ Common Signs & Organ Involvement

• Respiratory signs: Chronic cough, dyspnea, pleural effusion :contentReference[oaicite:5]{index=5}.
• Skin/subcutaneous nodules: Firm masses on limbs or trunk :contentReference[oaicite:6]{index=6}.
• Ocular lesions: Clouding, corneal edema, inflammation in one case :contentReference[oaicite:7]{index=7}.
• Systemic signs: Lethargy, anorexia, weight loss, fever :contentReference[oaicite:8]{index=8}.

🧬 Pathophysiology & Cell Type

Unlike human LYG (B-cell driven, EBV-associated), feline LYG shows **T-cell predominance**. Neoplastic T lymphocytes invade blood vessels, triggering tissue necrosis and granulomatous inflammation :contentReference[oaicite:9]{index=9}.

🔬 Diagnosing LYG

Diagnosis requires a multi-pronged approach:

• History & exam: Note respiratory distress and peripheral nodules :contentReference[oaicite:10]{index=10}.
• Imaging: Chest X-ray/CT may reveal lung consolidation and pleural effusion :contentReference[oaicite:11]{index=11}.
• Thoracocentesis: Analysis may show neoplastic effusion :contentReference[oaicite:12]{index=12}.
• Biopsy/FNA: Required from lung, skin, or ocular lesions; histopathology shows angioinvasion :contentReference[oaicite:13]{index=13}.
• Tissue techniques: Immunophenotyping (CD3+), PCR for antigen receptor rearrangement (PARR) confirms T-cell origin :contentReference[oaicite:14]{index=14}.

💊 Treatment & Management

There is **no definitive cure**, but several interventions can be attempted:

• Surgical excision: If lesions are localized—e.g. solitary lung mass, skin nodule :contentReference[oaicite:15]{index=15}.
• Corticosteroids: High-dose dexamethasone may yield temporary improvement :contentReference[oaicite:16]{index=16}.
• Chemotherapy: Protocols such as CHOP-based drugs or vincristine have been used :contentReference[oaicite:17]{index=17}.
• Palliative care: Oxygen support, fluid therapy, pain control for comfort ◦ monitoring.

Unfortunately, reports show rapid progression: one cat euthanized within weeks despite surgery and treatment; another deteriorated despite corticosteroids and chemo :contentReference[oaicite:18]{index=18}.

📅 Prognosis & Follow-Up

Prognosis is **guarded to poor**:

• Progression often rapid.
• Median survival measured in **weeks to few months**.
• Recurrences and metastases are common :contentReference[oaicite:19]{index=19}.
• Frequent rechecks every 2–4 weeks recommended to assess therapy response.

🐾 Supportive Care & Home Management

• Respiratory support: Offer oxygen or steam therapy for difficulty breathing.
• Pleural drainage: Perform thoracocentesis at home if instructed, or hospital visits.
• Pain & appetite: Use safe NSAIDs/opioids, enticing wet foods, appetite stimulants.
• Comfortable setup: Calm, warm environment, easy access to litter and food.
• Owner education: Recognize respiratory distress, bleeding, anorexia—seek vet care.
• Remote support: Ask A Vet app can guide home care decisions anytime.
• Stress reduction: Use calming Woopf & Purrz products to ease environment.

📝 Summary Table