Thyroid gland
Papillary carcinoma
Cribriform-morular variant

Topic Completed: 2 March 2009

Minor changes: 2 June 2020

Copyright: 2003-2019,, Inc.

PubMed Search: cribriform-morular variant

Shahid Islam, M.D., Ph.D.
Page views in 2019: 2,958
Page views in 2020 to date: 1,344
Cite this page: Islam S. Cribriform-morular variant. website. Accessed June 4th, 2020.
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

Contributed by Drs. Safa Alshaikh and Aalaa Mohammed:

Case of the Week #470

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)
Cytology images

Contributed by Drs. Safa Alshaikh and Aalaa Mohammed:

May Grunwald Giemsa (MGG)

Pap stain

IHC Stains

Contributed by Drs. Safa Alshaikh and Aalaa Mohammed:


Virtual slides

Images hosted on other servers:
Positive stains
Electron microscopy description
Board review style question #1
What syndrome is associated with cribriform morular variant of thyroid carcinoma?

A. Carney complex
B. Familial adenomatous polyposis
C. Cowden syndrome
D. Gardner syndrome
Board review answer #1
B. Familial adenomatous polyposis
Familial adenomatous polyposis is a rare condition transmitted in an autosomal dominant pattern related to germline mutation of the tumor suppressor gene APC, which strongly predisposes to colorectal cancer. Thyroid carcinoma rarely coexists with FAP (in just 0.3-1.2% of cases). When it does, it is almost exclusively CMV-PTC.

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