Stage grouping for medullary thyroid carcinoma is the same as for papillary
or follicular carcinoma in people older than age 45.
Stage Grouping for Anaplastic/Undifferentiated Thyroid Carcinoma
All anaplastic thyroid cancers are considered as stage IV, reflecting the
poor prognosis of this type of cancer.
Stage IVA: T4a, any N, M0: Tumor of any size and has grown beyond the
thyroid gland to invade nearby tissues of the neck and may or may not have
spread to local neck nodes but not to distant sites.
Stage IVB: T4b, Any N, M0: Tumor of any size has grown either back to
the spine or into nearby large blood vessels, may or may not have spread to
lymph nodes, but has not spread to distant sites.
Stage IVC: Any T, any N, M1: Tumor is any size and may or may not
have spread to lymph nodes, but it has spread to distant sites.
Thyroid Carcinoma Stage Grouping
Papillary or FollicularUnder 45 Years
Stage I Any T Any N M0
Stage II Any T Any N M1
Papillary or Follicular45 Years and Older
Stage I T1 N0 M0
Stage IIT2 N0 M0
Stage III T3 N0 M0, T1 N1a M0, T2 N1a M0, or T3 N1a M0