Thyroid gland
Papillary carcinoma
Follicular variant

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

Revised: 15 December 2016, last major update March 2009

Copyright: (c) 2003-2016, PathologyOutlines.com, Inc.

PubMed search: papillary carcinoma [title] thyroid WITH follicular

Cite this page: Follicular variant. PathologyOutlines.com website. http://pathologyoutlines.com/topic/thyroidfollicularvariant.html. Accessed January 21st, 2017.
Definition / General
Diagnosis
Prognostic Factors
Case Reports
Micro Description
  • Wide fibrous bands incompletely divide tumor into lobules
  • Follicular architecture but papillary cytology
  • Usually infiltrative with fibrous trabeculation, psammoma bodies, strongly eosinophilic colloid with scalloping
  • Important diagnostic criteria include pseudoinclusions (cytoplasmic invaginations into nucleus), abundant nuclear grooves, ground glass nuclei (Am J Surg Pathol 2004;28:1336); also nuclear clearing, nuclear overlapping and crowding, nuclear enlargement
Micro Images
Scroll to see all images.

Images hosted on PathOut server:

Courtesy of Andrey Bychkov, M.D., Ph.D.

Bone fragment surrounded by tumor

Developing bone marrow

Infiltrative growth, follicular pattern, bright colloid

Oncocytic PTC:
eosinophilic cyto-
plasm, nuclei,
pseudoinclusions


Vesicular nuclei with irregular membranes

Evident major and minor diagnostic features

"Minor diagnostic
features" include dark
colloid with frequent
scalloping and clefting



Contributed by Dr. Mark R. Wick

Various Images



Images from AFIP:

Wide fibrous bands

Microfollicular and macrofollicular patterns

Macrofollicular
formations re-
semble nodular
hyperplasia

Clear cytoplasm

Nuclei are overlapping with empty appearance


Some neoplastic follicles lined by granular acidophilic cells

Clear cell change

Intraluminal colloid

Follicular pattern of papillary carcinoma at bottom

Various images



Images hosted on other servers:

Follicular epithelial cells have ground glass nuclei and occasional nuclear grooves

Vesicular nuclei and hemorrhage in follicular lumina

Crowded nuclei and scalloped colloid

Collision tumor with squamous cell carcinoma

Virtual Slides
Images hosted on other servers:

Van Gieson

Cytology Description
  • Increased cellularity, moderate thin watery colloid with variable eosinophilic colloid
  • Cells are in sheets, small acini or syncytial fragments
  • Nuclear enlargement, but may lack prominent nuclear features of papillary carcinoma (Am J Clin Pathol 1999;111:216)
  • Highly suggestive if syncytial clusters, microfollicular architecture, chromatin clearing and nuclear grooves (Acta Cytol 2006;50:663)
  • Ultrafast Papanicolaou stained smears makes clear nuclei more conspicuous (Cancer 2006;108:174)
Cytology Images
Images hosted on other servers:

Cellular aspirates
with some micro-
follicular aggre-
gates, no colloid

Acinar arrangement with intranuclear inclusion


Fig 1 (left): Ovoid and pear shaped hypochromatic nuclei and nuclear grooves; cells show nuclear
overlap, round / oval hypochromatic nuclei, eccentric small nucleoli, and nuclear grooves (arrow)
Fig 2 (center): Cells have powdery chromatin, nuclear grooves and intranuclear cytoplasmic inclusions
Fig 3 (right): Enlarged round / oval nuclei, but papillary nuclear features are difficult to appreciate

Positive Stains
  • Low and high molecular weight keratin
Molecular / Cytogenetics Description
Additional References