Parathormone Measurement in Wash-out of Fnab Aspirates for Localization of Primary Hyperparathyroidism

Presentation Number: MON 350
Date of Presentation: April 3rd, 2017

Guven BARIS Cansu1 and Bengur Taskiran*2
1Yunus Emre State Hospital, Eskisehir, Turkey, 2yunus emre state hospital, eskisehir, Turkey

Abstract

Introduction: Solitary adenoma is responsible for 85% of primary hyperparathyroidism (PHP). The proper treatment is surgical removal of parathyroid adenoma. Preoperative localization of the putative adenoma determines the success of the surgery. Ultrasound (USG) (sensitivity 72-85%) and 99mTc-MIBI scan (sensitivity 71-93%, spesificity 90%) may give both false positive (other cervical pathologies including nodular goiter) and false negative (small size or low activity) results.

In this study we present patients with PHPT, who underwent fine needle aspiration biopsy (FNAB) and PTH wash-out for localization of parathyroid lesion and parathyroidectomy afterwards.

Methods: In 2011-2016 data of 98 patients, who were diagnosed with PHP and in whom parathyroidectomy was indicated according to the Guideline for Surgery in Asymptomatic Primary Hyperparathyroidism (2014), were evaluated retrospectively. Seventy six patients with positive preoperative localization study with 99m Tecnethium methoxy isobutyl isonitrite (99 mTc-MIBI) (n=58) and those who did not undergo parathyroidectomy due to various reasons (nonapproval for surgery due to patient’s wishes or surgery risk factors, admission to other health facility) (n=18) were excluded. Neck ultrasound using 5-10 MHz linear array transducers (Mindray DC-T6 Diagnostic Ultrasound System, Shenzhen, China) was performed by two experienced endocrinologist. US guided biopsies were performed using sterile 25 gauge needles and 10 ml syringes. Biopsy samples were smeared on glass slides for cytologic examination. Immediately after aspiration biopsy, the needles were rinsed with 1 ml of normal saline solution and PTH was measured in the wash-out fluid. The wash-out samples with a PTH level above 300 pg/ml, were studied again after 1/10-100 dilution.

FNAB and PTH measurement in wash-out of the aspirates were performed in the remaining 22 patients with negative 99mTc-MIBI scan for localization. Serum and wash-out PTH levels and biochemical measurements along with cytology-histology reports were evaluated.

Results: All patients were female and underwent parathyroid adenomectomy. They had a mean age of 50±9 (31–65 years), serum Ca of 10.9±0.5 (10.3–12.7) mg/dl, serum PTH 285±156 (107.2–679) pg/ml, and PTH in wash-out fluid of 19 523±38 632 (1 410-166 000) pg/ml. Cytological evaluation revealed 9 nondiagnostic, 8 benign, 3 cells of indeterminate origin, 1 suspicious for malignanacy, and 1 atypia of unknown significance. According to the postoperative histological examination 21 patient had parathyroid adenoma and one had parathyroid carcinoma.

Conclusion: Our results showed that PTH wash-out of FNAB of MIBI negative lesions suspicious for parathyroid adenoma on neck ultrasound is a reliable and effective method for localization.

 

Nothing to Disclose: GBC, BT