Hürthle Cell Thyroid Carcinoma: Key Characteristics
Option C is correct: Hürthle cell carcinoma often metastasizes to cervical lymph nodes, and requires total thyroidectomy as definitive treatment. 1, 2
Analysis of Each Statement
A. Total Thyroidectomy is Adequate Treatment
This statement is TRUE. Total thyroidectomy is the standard surgical approach for Hürthle cell carcinoma, as recommended by the NCCN. 1 However, surgery alone is not always "adequate" - the complete treatment paradigm includes:
- Total thyroidectomy is mandatory (not lobectomy) due to the more aggressive behavior compared to other differentiated thyroid cancers 1
- Central neck dissection (level VI) should be performed if lymph nodes are positive 1
- Lateral neck dissection (levels II-IV) is indicated for positive nodes 1
- Prophylactic central neck dissection may be considered even with negative nodes (category 2B recommendation) 1
- TSH suppression therapy with levothyroxine is required for all patients 1
- Radioactive iodine ablation should be considered for residual thyroid tissue, though HCC has poor iodine uptake 1, 3
The critical pitfall is treating HCC with lobectomy alone, which leads to inadequate management of this potentially aggressive cancer. 1
B. Seldom Bilateral
This statement is TRUE. HCC typically presents as unifocal disease and is seldom bilateral. 4 However, one older study from 1997 reported that HCC is "frequently bilateral or multifocal within the thyroid gland," 2 which contradicts more recent guideline-based evidence. The NCCN guidelines indicate HCC most commonly presents as a solitary nodule. 1 The weight of current evidence supports that bilateral presentation is uncommon.
C. Often Metastasizes to Cervical Lymph Nodes
This statement is TRUE and represents the BEST answer. HCC is associated with a high rate of locoregional recurrence and lymph node metastases. 2 The NCCN specifically addresses lymph node management with detailed recommendations for both central and lateral neck dissection when nodes are positive. 1 At surgery, lymph node metastases are commonly present, requiring therapeutic neck dissection. 5 This characteristic distinguishes HCC from other differentiated thyroid cancers and drives the aggressive surgical approach.
D. Not Related to Previous Neck Radiation
This statement is TRUE. Unlike papillary thyroid carcinoma, there is no established association between Hürthle cell carcinoma and previous neck radiation exposure. 1 One case series reported only 1 out of 13 patients had a history of childhood head and neck radiation, 5 but this does not establish causation. Radiation history is listed as a high-risk feature for papillary thyroid carcinoma, 6 but not specifically for HCC.
Clinical Context and Prognosis
HCC represents approximately 3% of all thyroid carcinomas and is now classified by the WHO as a distinct type of differentiated thyroid cancer, not merely a variant of follicular carcinoma. 1, 4
The 10-year relative survival rate is approximately 76%, which is notably lower than papillary (93%) and follicular (85%) carcinomas, reflecting its more aggressive nature. 1
Risk stratification is critical:
- High recurrence risk (30-55%) occurs with extensive vascular invasion (>4 foci) 4
- HCC with extensive vascular and/or capsular invasion should be managed like other high-risk carcinomas 1
Radioiodine uptake is poor - fewer than 10% of HCC take up radioiodine, 3 though ablation should still be attempted for residual thyroid tissue. 1