Thyroid & parathyroid
Papillary thyroid carcinoma
Other subtypes
Solid / trabecular
Author: Shahid Islam, M.D., Ph.D.
Last author update: 1 March 2009
Last staff update: 5 May 2023 (update in progress)
Copyright: 2003-2023, PathologyOutlines.com, Inc.
PubMed Search: solid variant papillary thyroid carcinoma
Table of Contents
Definition / general | Prognostic factors | Case reports | Microscopic (histologic) description | Microscopic (histologic) images | Cytology images | Electron microscopy description | Differential diagnosisCite this page: Islam S. Solid / trabecular. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/thyroidsolidvariant.html. 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
- 64 year old man diagnosed by cytology and BRAF mutational analysis (Cytojournal 2008;5:2)
- Case with novel BRAF triplet deletion (Hum Pathol 2005;36:694)
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
septa
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
grooves
Electron microscopy description
- Solid / trabecular areas share similar ultrastructural features with poorly differentiated carcinomas (Ultrastruct Pathol 2001;25:13)
Differential diagnosis
