Hurthle cell Carcinoma of Thyroid

🧬 Hurthle Cell Carcinoma of Thyroid

📖 Definition of Hurthle Cell Carcinoma of Thyroid

Hurthle Cell Carcinoma is a malignant thyroid tumor composed predominantly of Hurthle cells.

It accounts for 3–10% of all differentiated thyroid cancers.

What are Hurthle cells?

What are some other names of Hurthle cells?

🧠 Historical Background

• Previously classified as: A variant of follicular carcinoma.

• Now (WHO classification): Recognized as an independent tumor type due to:

  • Distinct molecular alterations
  • Different biological behavior
  • Unique clinical course

Where does Hurthle Cell Carcinoma of Thyroid originate from?

👩‍🦳 Epidemiology of Hurthle Cell Carcinoma of Thyroid

• Age: More common in elderly individuals

• Sex: Predominantly females

• Incidence: 3–10% of differentiated thyroid malignancies

🔬 Cytological & Histological Features of Hurthle Cell Carcinoma of Thyroid

🔹 Hurthle Cells — The Characteristic Cell

What is the microscopic appearance of Hurthle cells?

🧫 Microscopy

• The tumor is usually encapsulated with a thick capsule.

• Sheets or nests of Hurthle cells with granular cytoplasm are seen.

• Capsular or vascular invasion must be demonstrated to confirm carcinoma (similar to follicular carcinoma).

📸 Key Diagnostic Point:
The presence of capsular and/or vascular invasion differentiates Hürthle cell carcinoma from Hürthle cell adenoma.

🩺 Clinical Features of Hurthle Cell Carcinoma of Thyroid

Patients usually present with:

• A thyroid nodule, which can be:

  • Solitary or multifocal
  • Unilateral or bilateral

• The swelling is typically firm and non-tender.

• More aggressive course than follicular carcinoma.

• Local invasion and recurrence are common.

Metastatic Spread:

• Hematogenous spread: To lungs, bone, liver

• Lymphatic spread: More common than in follicular carcinoma

🔍 Investigations of Hurthle Cell Carcinoma of Thyroid

1. Fine Needle Aspiration Cytology (FNAC)

• Shows presence of Hurthle cells.
• Cannot differentiate between adenoma and carcinoma — histological evidence of capsular/vascular invasion is essential.

1. CT Scan / MRI Neck

• Evaluates local extension and regional lymph nodes.

1. Bone Scan

• To detect bony metastases.

🧠 Note: Hurthle cell carcinoma may show reduced iodine uptake on radioisotope scanning.

💊 Treatment of Hurthle Cell Carcinoma of Thyroid

1️⃣ Surgery — Mainstay of Treatment

• Total Thyroidectomy is the treatment of choice.

Why is Total Thyroidectomy the treatment of choice in Hurthle Cell Carcinoma of Thyroid?

2️⃣ Radioiodine Ablation

• Not effective in most cases

Why is radioiodine therapy of limited benefit in Hurthle Cell Carcinoma of Thyroid?

3️⃣ Thyroid Hormone Suppression Therapy

• Lifelong TSH suppression with Levothyroxine is essential
  • Prevents stimulation of residual tumor cells.

📉 Prognosis of Hurthle Cell Carcinoma of Thyroid

Hürthle Cell Carcinoma has a worse prognosis compared to follicular carcinoma.

Why does Hurthle Cell Carcinoma of Thyroid have the worst prognosis?

🧾 Summary Table