RESUMO
BACKGROUND: Even though morphologic findings are generally important in the diagnosis of thyroid tumors, in some cases, morphologic similarities between benign and malignant lesions lead to noticeable differences in evaluation and different diagnoses in the same cases. In our study, we researched whether the autophagy-related protein Beclin-1 (BECN1) is a diagnostic marker in thyroid tumors, as well as its correlation with HBME-1, which has high sensitivity and specificity in distinguishing malignant thyroid lesions. METHODS: Samples from 136 patients that received a thyroidectomy were fixed in 10% formalin. All cases had hematoxylin & eosin (H&E) stains available for review and paraffin blocks for immunohistochemical staining. In immunochemistry tests, BECN1, HBME-1, and Ki-67 were studied. RESULTS: BECN1 immunoreactivity rates were found to be 98.9% in papillary thyroid carcinoma (PTC), 57.1% in follicular carcinoma (FC), and 21.4% in follicular adenoma (FA). HBME-1 immunoreactivity was 100% in PTC, 85.7% in FC, and 64% in FA. In thyroid carcinomas, BECN1 was as effective as HBME-1 as a marker for the diagnosis of malignancy. CONCLUSIONS: We revealed an important role of autophagy in thyroid carcinogenesis, as evidenced by the high rate of BECN1 immunoreactivity in PTC and FC. Moreover, we found that autophagy plays a more important role in PTC, as evidenced by the high immunoreactivity rates. According to our results, BECN1 is a more specific marker than HBME-1 in PTC and has a higher correlation with Ki-67. In routine studies, BECN1 will be more helpful than HBME-1 in the diagnosis of PTC.
