WORLD JOURNAL OF ADVANCE
HEALTHCARE RESEARCH

*Sahar Naseer Mahmood, Haider Jebur Kehiosh

ABSTRACT

Background: Noninvasive follicular thyroid neoplasm with papillary-like nuclear features (NIFTP) was introduced by the WHO in 2016 as a distinct diagnostic category, characterized by indolent behavior and lack of recurrence or metastasis. While classical papillary thyroid carcinoma (CPTC) is strongly associated with BRAFV600E mutations, follicular-patterned neoplasms, including NIFTP, are usually driven by RAS or RAS-like mutations and rarely harbor BRAFV600E. Recently, reliable immunohistochemistry (IHC) for BRAFV600E has emerged as a useful molecular surrogate in thyroid pathology. Objective: To evaluate the utility of BRAFV600E immunohistochemistry as a diagnostic adjuvant in the exclusion of NIFTP. Methods: A cross-sectional study was conducted on 61 thyroid tumors, including 30 cases of NIFTP and 31 cases of follicular variant papillary thyroid carcinoma (FVPTC), diagnosed at multiple centers in Karbala, Iraq, between January 2022 and June 2024. All samples were assessed for BRAFV600E expression using IHC. Results: Among NIFTP cases, 18 (60%) were negative and 12 (40%) were positive for BRAFV600E. In contrast, 22 of 31 FVPTC cases (71%) were positive and 9 (29%) were negative. BRAFV600E positivity was significantly higher in FVPTC than NIFTP (p = 0.021). No significant association was observed between BRAFV600E status and age, gender, tumor size, or focality. Both invasive encapsulated FVPTC (71.4%) and infiltrative FVPTC (70.6%) demonstrated high BRAFV600E positivity with no significant difference between subtypes. Conclusion: BRAFV600E IHC serves as a valuable diagnostic adjuvant for excluding NIFTP. Positive staining supports a diagnosis of FVPTC, particularly invasive subtypes, and aids in refining diagnostic accuracy when histologic features are ambiguous.