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Updated: May 11, 2026
05:39
Spontaneous Murine Model of Anaplastic Thyroid Cancer
Published on: February 3, 2023
Napsin A expression in anaplastic, poorly differentiated, and micropapillary pattern thyroid carcinomas
Rebecca D Chernock1, Samir K El-Mofty, Nils Becker
1Department of Pathology and Immunology, Washington University School of Medicine, St Louis, MO, USA. rchernock@path.wustl.edu
The American Journal of Surgical Pathology
|May 18, 2013
Summary
Napsin A, a lung adenocarcinoma marker, can appear in aggressive thyroid cancers, particularly those with a micropapillary pattern. PAX8 helps differentiate these thyroid tumors from lung cancers.
Area of Science:
- Oncology
- Pathology
- Molecular Diagnostics
Background:
- Napsin A is a key marker for pulmonary adenocarcinoma.
- Napsin A positivity is observed in a small percentage of papillary thyroid carcinomas.
- The expression of Napsin A in aggressive thyroid carcinoma subtypes is not well-established.
Purpose of the Study:
- To determine the prevalence of Napsin A in anaplastic, poorly differentiated, and micropapillary pattern thyroid carcinomas.
- To evaluate the utility of Napsin A, TTF-1, and PAX8 in differentiating thyroid carcinomas from lung adenocarcinoma.
Main Methods:
- Immunohistochemical analysis of Napsin A, TTF-1, and PAX8 expression.
- Study cohort included 26 anaplastic, 16 poorly differentiated, and 2 micropapillary thyroid carcinomas.
- Cases with focal micropapillary components were also analyzed.
Main Results:
- Napsin A positivity was found in 15% of anaplastic, 13% of poorly differentiated, and 100% of micropapillary thyroid carcinomas.
- Napsin A expression was more frequent in thyroid carcinomas with a micropapillary component.
- All Napsin A-positive thyroid cases also expressed TTF-1; most also expressed PAX8.
Conclusions:
- A subset of aggressive thyroid carcinomas, especially those with a micropapillary pattern, can express Napsin A.
- Co-expression of Napsin A and TTF-1 in thyroid carcinoma can mimic lung adenocarcinoma.
- PAX8 expression serves as a valuable marker to distinguish Napsin A-positive thyroid carcinomas from lung adenocarcinomas.
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