Thyroid gland
Papillary carcinoma
Diffuse follicular variant

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

Revised: 23 February 2017, last major update March 2009

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

PubMed search: papillary carcinoma thyroid follicular

Cite this page: Diffuse follicular variant. website. Accessed June 20th, 2018.
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