Thyroid & parathyroid

Papillary thyroid carcinoma

Other subtypes

Solid / trabecular

Last author update: 1 March 2009
Last staff update: 5 May 2023 (update in progress)

Copyright: 2003-2023,, Inc.

PubMed Search: solid variant papillary thyroid carcinoma

Shahid Islam, M.D., Ph.D.
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Cite this page: Islam S. Solid / trabecular. website. Accessed November 29th, 2023.
Definition / general
  • 50 - 70% or more solid growth pattern with papillary cytologic features, without necrosis
  • Rare in adults (3% of all papillary carcinomas)
  • In children, solid / trabecular variant is very common, has higher risk of relapse (Am J Surg Pathol 2006;30:1420)
  • Also seen in post-Chernobyl cases associated with RET / PTC3 rearrangement (J Clin Endocrinol Metab 1999;84:4232)
Prognostic factors
  • Associated with slightly poorer prognosis and slightly more distant metastases than classic papillary carcinoma but better prognosis than poorly differentiated carcinoma (Am J Surg Pathol 2001;25:1478)
Case reports
Microscopic (histologic) description
  • Unencapsulated with invasive borders
  • Composed of round solid nests resembling filled up follicles, surrounded by fibrous / hyaline stroma
  • May have vague papillary or follicular formations
  • Nuclear features of papillary carcinoma are present
Microscopic (histologic) images

Images hosted on other servers:

Solid architecture
traversed by
delicate fibrous

Classic nuclear features of papillary thyroid carcinoma

Fig 3D: RET staining

Cytology images

Images hosted on other servers:

Solid aggregates of epithelial follicular cells

Monolayered epithelial cellular sheets

Enlarged nuclei
with fine chromatin,
occasional nuclear

Electron microscopy description
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