Thyroid gland
Papillary carcinoma
Cribriform-morular variant

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

Revised: 1 February 2017, last major update March 2009

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

PubMed Search: cribriform-morular variant
Cite this page: Cribriform-morular variant. website. Accessed October 22nd, 2018.
Definition / general
  • Cribriform growth pattern and morular formations
  • Rare, 0.2% of papillary thyroid carcinoma (World J Surg 2004;28:886); associated with sporadic or germline mutations of APC gene (Am J Clin Pathol 2001;115:486)
  • Presence of tumor may suggest colon cancer screening for the patient due to association with familial adenomatosis polyposis
Clinical features
  • These lesions are usually associated with familial adenomatosis polyposis (FAP) but rarely may be sporadic (Int J Med Sci 2004;1:43)
Prognostic factors
Case reports
Microscopic (histologic) description
  • Tumors are encapsulated or circumscribed with cribriform, solid, papillary, tall columnar and morular patterns
  • Contains follicles without colloid, papillary formations of tall cells with abundant eosinophilic cytoplasm and pseudostratification, hyperchromatic nuclei with grooves and pseudoinclusions
  • Morular (squamoid) metaplasia with nuclear clearing resembling viral inclusions
  • Also spindle cells
  • Vascular and capsular invasion common
Microscopic (histologic) images

Images hosted on other servers:

Complex branching
papillary structures
with papillary
carcinoma nuclear

Blending of various histologic patterns

Whorls of cells forming
squamoid morules or nests
without keratinization
or intercellular bridges

Cribriform areas have back to
back follicles with anastomosing
bars and arches of cells,
and no fibrovascular stroma

Cytology description
  • Papillary fragments and acini composed of columnar cells with fine to granular chromatin and nuclear grooves
  • Also occasional groups of epithelial cells forming morules (Acta Cytol 2005;49:75)
Positive stains
Electron microscopy description