Monoclonal/polyclonal PAX-8, PTH and GATA3 immunohistochemistry in parathyroid lesions.

Abstract

Parathyroid gland (PG) is an endocrine organ which may display different immunohistochemical stainings with chief cells and oxyphilic cells in normal as well as hyperplasic/tumoral lesions. In this study, we aimed to identify the demographic properties and diagnostic value of the GATA3 antibody, which is a transcription factor in addition to PTH, and of PAX-8 (monoclonal and polyclonal) antibody. We have analyzed in detail the cellular components and staining intensities of 46 adenomas all of which contained parathyroid rims, 12 hyperplasia and 5 adjacent non-neoplastic thyroidectomy materials (63 patients, 114 tissues). While no staining was identified in the thyroid tissue, cytoplasmic PTH immunoreactivity was observed in all (100%) normal parathyroid tissues, rim of PGs and hyperplasia, and in 43/46 cases (93.4%) of adenomas. Adenoma and hyperplasia were less stained than normal PG (p < 0.05). We detected GATA3 staining in all cases except for the thyroid (100%). Weak positivity (1+) was most apparent in adenoma cases (p < 0.05). Monoclonal PAX-8 immunoreactivity was not identified in any normal parathyroid tissue and rim of PG but positive immunoreactivity was detected in 83.3% of hyperplasia cases (10/12), 84.8% of adenoma (39/46) and 100% of thyroid tissues (5/5) (p < 0.05). However, polyclonal PAX-8 immunoreactivity was detected in one normal parathyroid tissue (1/5) and seven (7/46) rim of PGs. In cases of hyperplasia and adenoma, positive immunoreactivity was 75% (9/12) and 74% (34/46), respectively. In conclusion, we have observed that PTH and GATA3 constitute a much more reliable and sensitive marker for parathyroid and are stained less in adenomas. While monoclonal PAX-8 (MRQ-50) never stains normal parathyroid and rim of PGs, it may help in the differential diagnosis of proliferated parathyroid lesions as a considerably sensitive and relatively specific marker by staining hyperplasic parathyroid, adenomas and the thyroid.