Follicular thyroid cancer staging
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Differentiating Follicular thyroid cancer from other Diseases |
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Follicular thyroid cancer staging On the Web |
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American Roentgen Ray Society Images of Follicular thyroid cancer staging |
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Risk calculators and risk factors for Follicular thyroid cancer staging |
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Ammu Susheela, M.D. [2]
Overview
According to the American Joint Committee on Cancer (AJCC)[1] there are 4 stages of follicular thyroid cancer based on the clinical features and findings on imaging. Each stage is assigned a letter and a number that designate the tumor size, number of lymph node regions involved, and metastasis.
Staging
| Stage | Description |
|---|---|
| TX | Primary tumor cannot be assessed |
| T0 | No evidence of primary tumor |
| T1 | Tumor ≤2 cm in greatest dimension limited to the thyroid |
| T1a | Tumor ≤1 cm, limited to the thyroid |
| T1b | Tumor >1 cm but ≤2 cm in greatest dimension, limited to the thyroid |
| T2 | Tumor >2 cm but ≤4 cm in greatest dimension, limited to the thyroid |
| T3 | Tumor >4 cm in greatest dimension limited to the thyroid or any tumor with minimal extrathyroid extension (e.g., extension to sternothyroid muscle or perithyroid soft tissues) |
| T4a | Moderately advanced disease |
| Tumor of any size extending beyond the thyroid capsule to invade subcutaneous soft tissues, larynx, trachea, esophagus, or recurrent laryngeal nerve | |
| T4b | Very advanced disease |
| Tumor invades prevertebral fascia or encases carotid artery or mediastinal vessel |
| Stage | Description |
|---|---|
| NX | Regional lymph node cannot be assessed |
| N0 | No regional lymph node metastasis |
| N1 | Regional lymph node metastasis |
| N1a | Metastases to Level VI (pretracheal, paratracheal, and prelaryngeal/Delphian lymph nodes) |
| N1b | Metastases to unilateral, bilateral, or contralateral cervical (Levels I, II, III, IV, or V) or retropharyngeal or superior mediastinal lymph nodes (Level VII) |
| Stage | Description |
|---|---|
| M0 | No distant metastasis |
| M1 | Distant metastasis |
| Stage | T | N | M |
|---|---|---|---|
| Follicular thyroid carcinoma | |||
| YOUNGER THAN 45 YEARS | |||
| I | Any T | Any N | M0 |
| II | Any T | Any N | M1 |
| 45 YEARS AND OLDER | |||
| I | T1 | Any N | M1 |
| II | T2 | N0 | M0 |
| III | T3 | N0 | M0 |
| T1 | N1a | M0 | |
| T2 | N1a | M0 | |
| T3 | N1a | M0 | |
| IVA | T4a | N0 | M0 |
| T4a | N1a | M0 | |
| T1 | N1b | M0 | |
| T2 | N1b | M0 | |
| T3 | N1b | M0 | |
| T4a | N1b | M0 | |
| IVB | T4b | Any N | M0 |
| Stage IVC | Any T | Any N | M1 |
Follicular Thyroid Cancer
Stage I Follicular Thyroid Cancer
- Stage I follicular carcinoma is localized to the thyroid gland. Follicular thyroid carcinoma must be distinguished from follicular adenomas, which are characterized by their lack of invasion through the capsule into the surrounding thyroid tissue.
Stage II Follicular Thyroid Cancer
- Stage II follicular carcinoma is defined as either tumor that has spread distantly in patients younger than 45 years, or tumor that is larger than 2 cm but smaller than 4 cm and is limited to the thyroid gland in patients older than 45 years. The presence of lymph node metastases does not worsen the prognosis among patients younger than 45 years. Follicular thyroid carcinoma must be distinguished from follicular adenomas, which are characterized by their lack of invasion through the capsule into the surrounding thyroid tissue. While follicular cancer has a good prognosis, it is less favorable than that of papillary carcinoma. The 10-year survival is better for patients with follicular carcinoma without vascular invasion than for patients with vascular invasion.
Stage III Follicular Thyroid Cancer
- Stage III follicular carcinoma in patients older than 45 years is defined as tumor larger than 4 cm and limited to the thyroid or with minimal extrathyroid extension, or lymph node involvement limited to the pretracheal, paratracheal, or prelaryngeal/Delphian nodes.
Stage IV Follicular Thyroid Cancer
- Stage IV follicular carcinoma in patients older than 45 years is defined as tumors with extension beyond the thyroid capsule to the soft tissues of the neck, cervical lymph node metastases, or distant metastases. The lungs and bone are the most frequent sites of spread. Follicular carcinomas more commonly have blood vessel invasion and tend to metastasize hematogenously to the lungs and to the bone rather than through the lymphatic system.
Reference
- ↑ Stage Information for Thyroid Cancer Cancer.gov (2015). http://www.cancer.gov/types/thyroid/hp/thyroid-treatment-pdq#link/stoc_h2_2- Accessed on October, 29 2015