Use of HBME-1, p27 and Galectin-3 Triple Immunostaining in Cytology and Histology Specimens To Help Clarify Follicular Lesions of Undetermined Significance (FLUS)
Lei Zhang, Thomas Krausz, Ward Reeves, Ghazal Khan, Richard M DeMay. University of Chicago, Chicago, IL
Background: Galectin-3 is the downstream target of PAX8/PPARγ translocation and HBME-1 is the downstream target of RAS activation. These two mutually exclusive pathways can lead to development of follicular carcinoma. Noteworthy, most papillary carcinomas express HBME-1, and some of papillary carcinomas grow as follicular-patterned lesions. The combined use of Galectin-3 and HBME-1 increases sensitivity of diagnosing follicular carcinoma and papillary carcinoma. P27 (kip1) is an inhibitor of G1/S cell cycle progression, and is highly expressed in normal thyroid follicular cells. Loss of p27 expression has been observed in over 85% of thyroid cancers. We hypothesize that Galectin-3, HBME-1 and p27 triple immunostaining would help clarify follicular lesions of undetermined significance of thyroid.
Design: A triple immunostaining protocol, using destained liquid based cytology (LBC) slides and formalin fixed paraffin embedded tissue (FFPE) slides, was developed in our lab. This protocol was applied to matched cytology and surgical pathology specimens retrospectively selected from 9 patients with a preoperative cytologic diagnosis of follicular lesion of undetermined significance (FLUS).
Results: The immunochemical staining pattern was similar in the matched LBC slides and the FFPE slides from the 9 patients. The 4 benign lesions (1 lymphocytic thyroiditis with adenomatoid hyperplasia, 2 adenomatoid nodules, 1 follicular adenoma) were negative (3/4) or scattered (<5%) positive (1/4) for HBME1/Galectin-3, and variably positive for p27 (4/4). The 5 malignant lesions (2 minimally invasive follicular carcinomas, 3 papillary carcinomas) were all diffusely positive for HBME1 and negative for p27 (5/5).
Conclusions: Our pilot study of triple immunostaining using a panel markers of HBME-1, Galectin-3 and p27 showed promising results in clarifying thyroid follicular lesions in both cytology and histology specimen. Further study is suggested to validate this assay.
Tuesday, March 5, 2013 1:00 PM
Poster Session IV # 87, Tuesday Afternoon