[374] Utility of Parathyroid Hormone Rinse Levels in Conjunction with Fine Needle Aspiration Cytology in the Evaluation of Indeterminate Parathyroid Neck Nodules

Susan L Haley, Michael W Riben, Beverly C Handy, Nancy P Caraway. University of Texas MD Anderson Cancer Center, Houston, TX

Background: Fine needle aspirates (FNAs) of nodules radiographically indeterminate for parathyroid (PT) vs. thyroid tissue or unsuspected parathyroid lesions (PTL) can be diagnostically challenging. This study evaluates the utility of chemical analysis for parathyroid hormone performed on the aspirate rinse solution (PTH-r) in diagnosing these indeterminate lesions.
Design: The pathology database was searched for patients (pts) who had an ultrasound (US) guided FNA of the head and neck region with concurrent PTH-r analysis. The PTH-r levels were correlated with the cytologic features, histologic findings, and clinical data including serum calcium (Ca++) and intact serum PTH (PTH-s) levels. In this study, PTH-r was considered elevated if >1000 pg/dL.
Results: There were 10 pts (5 men and 5 women) who met the study criteria. By US, the FNA sites were designated as parathyroid (3 cases), thyroid (1 cases), indeterminate for PT (4 cases), thyroid bed (1 case), and neck (1 case). Nodules ranged in size from 0.8 to 3 cm (mean, 2.2 cm) in largest diameter. Elevated PTH-s and serum Ca++ levels were present in 7 of 8 and 5 of 9 pts tested, respectively. Six pts had elevated PTH-r levels, and in 5 of these, the cytologic diagnoses were PTL or PTL was in the differential; the other was insufficient for diagnosis (cystic lesion). Histologic follow-up was available for 6 pts. In 5 pts with high PTH-r levels, histology showed 4 PT adenomas (1 intrathyroid) and 1 PT hyperplasia. One pt without elevated PTH-r levels, but PTL on cytology, had a PT adenoma on excision. The remaining 4 pts were followed clinically, including 1 pt with high PTH-r levels and MEN1 syndrome with recurrent hyperparathyroid disease.
Conclusions: FNA with PTH-r has utility in differentiating PT from thyroid lesions in indeterminate nodules by US, FNA or paucicellular specimens. It is important to correlate the cytologic findings with the PTH-r levels. FNA with PTH-r is a useful approach in guiding clinical management, especially in patients with elevated serum Ca++ and/or PTH levels.
Category: Cytopathology

Tuesday, March 5, 2013 1:00 PM

Poster Session IV # 100, Tuesday Afternoon


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