Thyroid gland
Variations of normal thyroid gland

Author: Shahidul Islam, M.D., Ph.D. (see Authors page)

Revised: 16 January 2017, last major update March 2009

Copyright: (c) 2003-2017,, Inc.

PubMed Search: variations thyroid gland

See also Parathyroid tissue, Thymic tissue
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Cite this page: Variations of normal thyroid gland. website. Accessed January 21st, 2019.
Definition / general
  • Adipose metaplasia (mature adipose tissue between follicles or near capsule)
  • Intrathyroidal cartilage, skeletal muscle or salivary gland
  • Melanosis of follicular cells in old age (pigment granules also contain colloid, Ultrastruct Pathol 1998;22:401); see also Black thyroid
  • Calcification is associated with vessels in elderly, has no laminations (in contrast to psammoma bodies)
  • Squamous metaplasia is rare in normal thyroid, more common in thyroid disorders
Case reports
Microscopic (histologic) images

Images hosted on PathOut server:

Images from AFIP:

Ectopic cartilage

Skeletal muscle

Squamous metaplasia