McGill Thyroid Nodule Score (MTNS)

The McGill Thyroid Nodule Score (MTNS) is a scoring system developed to estimate the risk of malignancy of thyroid nodules.1

Scoring system

The MTNS is based on 22 parameters:

  • eight clinical or laboratory parameters:
    • gender (male): 1 point
    • age (>45 years old): 1 point
    • palpable nodule (present): 1 point
    • TSH level (>1,4 mIU/L): 1 point
    • consistency (stone/bone hard):  2 points
    • ionizing radiation exposure: 3 points
    • family history of thyroid cancer: 3 points
    • ethnicity (Hawaiian, Filipino, Icelandic): 3 points
  • eight imaging findings:
    • hypoechoic nodule: 1 point
    • increased vascularity at color Doppler: 1 point
    • shape (taller than wide): 1 point
    • calcifications:  
      • coarse calcifications: 1 point
      • microcalcifications: 2 points
    • enlarging:  
      • >10%: 1 point
      • >30%: 2 points
    • lymphadenopathy (present): 2 points
    • size:
      • 2.0 - 2.9 cm: 2 points
      • 3.0 - 3.9 cm: 3 points
      • 4 cm or greater: 4 points
    • PET scan focally positive: 4 points
  • six cytological or molecular results:
    • Hürthle cell lesion (present): 2 points
    • favour neoplasm (present): 3 points
    • atypia (non reactive):  
      • mild: 3 points
      • moderate: 4 points
      • severe: 5 points
    • suspicious for malignancy (present): 7 points
    • HBME-1 (positive): 7 points
    • BRAF mutation (present): 7 points
Score Interpretation and percentage of risk of malignancy
  • 0 point = 0% 
  • 1-3 points = 27%
  • 4-7 points = 32%
  • 8 points = 39%
  • 9-11 points = 63%
  • 12-13 points = 88%
  • 14-18 points = 93%
  • >18 points = 100%

Practical points

Some think the MTNS is useful when the result of FNA is indeterminate.

The "mild", "moderate", and "severe" classification refers to subclassifications within the Bethesda 3 category. This is not always available on pathology reports.

Share article

Article information

rID: 44393
System: Head & Neck
Synonyms or Alternate Spellings:
  • MTNS

Support Radiopaedia and see fewer ads

Updating… Please wait.
Loadinganimation

Alert accept

Error Unable to process the form. Check for errors and try again.

Alert accept Thank you for updating your details.