Normal parathyroid length is which of the following?

Normal parathyroid length is which of the following?

• A. 1 to 2 mm
• B. 3 to 4 mm
• C. 5 to 7 mm
• D. 8 to 9 mm

Answer: (C)

Normal parathyroid glands are very small, and their size is assessed in the long axis on ultrasound. A length of about five to seven millimeters is typically considered normal. This size range reflects the small, discreet nature of the glands. Measurements much smaller (1–2 mm or 3–4 mm) are unlikely for a fully visualized normal gland and may reflect measurement limitations or very small glands, while a length around 8–9 mm would raise concern for enlargement, which could suggest hyperplasia or an adenoma and would prompt further correlation with labs and possibly additional imaging. Remember that exact sizing can vary with technique and patient anatomy, and clinical correlation is essential.

Normal parathyroid glands are very small, and their size is assessed in the long axis on ultrasound. A length of about five to seven millimeters is typically considered normal. This size range reflects the small, discreet nature of the glands. Measurements much smaller (1–2 mm or 3–4 mm) are unlikely for a fully visualized normal gland and may reflect measurement limitations or very small glands, while a length around 8–9 mm would raise concern for enlargement, which could suggest hyperplasia or an adenoma and would prompt further correlation with labs and possibly additional imaging. Remember that exact sizing can vary with technique and patient anatomy, and clinical correlation is essential.