Value of cytokeratin-19, Hector Battifora mesothelial-1 and galectin-3 immunostaining in the diagnosis of thyroid neoplasms

BACKGROUND: Diagnosis of types and aggressiveness of thyroid cancers is difficult. The “gold standard” in diagnosis is using routine hematoxylin and eosin staining. Several markers have been investigated for differentiating them among which cytokeratin-19 (CK-19), Hector Battifora mesothelial cell (HBME-1), and galectin-3 are found to be most commonly used. Most studies have evaluated the single expression of markers in various thyroid lesions. AIMS AND OBJECTIVES: To know the value of immunohistochemical expression of CK-19, HBME-1, and galectin-3 in diagnosing thyroid neoplasms. To study the expression and compare the results of HBME-1, CK-19, and galectin-3 immunohistochemical markers in histopathologically diagnosed malignant lesions and nonmalignant lesions and demonstrate their usefulness in differentiating them. MATERIALS AND METHODS: A prospective study was carried out on thyroidectomy specimens sent in 10% buffered formalin to Department of Pathology, SVIMS, Tirupati, from May 2013 to August 2014. Sensitivity and specificity for each marker and their combination in diagnosis were calculated. RESULTS: Among 120 cases, nonmalignant lesions were 70 (58.33%) and malignant lesions 50 (41.67%). Among nonmalignant lesions, 65 (93%) were adenomatous goiter and 5 (7%) were follicular adenomas. In malignant lesions, 48 (96%) were papillary carcinoma and 1 (2%) each of follicular carcinoma and anaplastic carcinoma. Among papillary carcinomas, classical were 26 (54.16%) followed by 17 follicular variant (35.41%). Galectin-3 had highest sensitivity of 90% and HBME-1 had highest specificity of 97.14%. CONCLUSIONS: Panel of HBME-1+ galectin-3 or CK-19, HBME-1, and galectin-3 increase the accuracy of diagnosis in histopathologically difficult cases.