Thyroid gland
Papillary thyroid carcinoma
Follicular patterned
Diffuse follicular

Topic Completed: 1 March 2009

Minor changes: 16 July 2020

Copyright: 2003-2017,, Inc.

PubMed search: papillary carcinoma thyroid follicular

Shahid Islam, M.D., Ph.D.
Page views in 2019: 1,244
Page views in 2020 to date: 493
Cite this page: Islam S. Diffuse follicular. website. Accessed August 8th, 2020.
Definition / general
  • Tumor involvement of most of a lobe or both lobes by follicular variant of papillary carcinoma
  • Uncommon (1 - 2% of papillary thyroid carcinomas at most)
  • Younger patients than those with classic papillary carcinoma
  • Aggressive with more extrathyroidal extension, nodal metastases and vascular invasion than classic (encapsulated) follicular variant of papillary thyroid carcinoma (Virchows Arch 2002;440:418, Cancer 2006;107:1255)
  • Also called nonencapsulated / infiltrative
Microscopic (histologic) description
  • Diffuse or micronodular pattern of growth
  • More intratumoral fibrosis than classic variant
Microscopic (histologic) images

Images hosted on PathOut server:

Contributed by Andrey Bychkov, M.D., Ph.D.:

Infiltrative growth,
exclusive follicular
pattern, bright colloid

Images hosted on other servers:

Tumor from 53 year old man
with metastatic carcinoma in
13 / 19 cervical lymph nodes (fig. 2)

Differential diagnosis
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