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BRAFV600E mutation in papillary thyroid microcarcinoma: a genotype-phenotype correlation.
Renu K Virk1, Alison L Van Dyke, Alexander Finkelstein
1Department of Pathology, Yale School of Medicine, New Haven, CT, USA.
Summary
The BRAF(V600E) mutation is common in papillary thyroid microcarcinoma and linked to aggressive features like infiltrative borders and lymph node metastasis. This mutation appears early in thyroid cancer development.
Area of Science:
- Endocrinology
- Oncology
- Molecular Biology
Background:
- The BRAF(V600E) mutation is a known marker for aggressive papillary thyroid carcinoma.
- Its role in papillary thyroid microcarcinoma, a smaller form of the cancer, is less understood.
Purpose of the Study:
- To investigate the clinicopathologic significance of the BRAF(V600E) mutation in papillary thyroid microcarcinomas.
- To determine if the mutation is associated with aggressive features or specific histologic subtypes.
Main Methods:
- BRAF(V600E) mutation analysis using single-strand conformation polymorphism in 129 papillary thyroid microcarcinomas.
- Examination of clinicopathologic features including tumor size, multifocality, nodal metastases, and histologic subtype.
Main Results:
- BRAF(V600E) mutation was found in 70% of cases and was significantly associated with infiltrative borders, stromal desmoplasia, classic nuclear features, and cystic change.
- Mutation prevalence varied by subtype, being higher in classic and tall cell variants compared to the follicular variant.
- Mutated tumors showed a higher frequency of lymph node metastases and extrathyroidal extension.
Conclusions:
- BRAF(V600E) mutation is an early event in papillary thyroid microcarcinoma development.
- The mutation is linked to specific morphological characteristics and aggressive behavior, even in small tumors.
- Absence of the mutation was primarily associated with the follicular variant of papillary microcarcinoma.
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