High Resolution Ultrasound Guided Needle Aspirate of Parathyroid Lesion; A Preliminary But Accurate Approach to Preoperative Identification and Localization of Parathyroid Adenoma

Abstract

Objective: To determine the sensitivity and specificity of high resolution ultrasound guided
FNAC as a preliminary but accurate investigation for identification and localization of parathyroid
adenoma for minimally invasive surgical road mapping to position the incision directly over the
diseased gland.
Material and Methods: This cross sectional study was conducted in Department of Radiology,
Omer hospital, Lahore, between September 2012 and September 2013. The study included
series of 13 patients, including 5 men and 8 women, ranging between 35 and 70 years (mean,
48.5±13 years). Neck ultrasound for parathyroid glands was performed in the patients presented
with non-specific symptoms of hypercalcaemia. Serological analysis included serum calcium,
serum PTH, alkaline phosphatase and creatinine. Exact size, location and number of parathyroid
adenomas were assessed followed by US-guided FNA.
Results: In 12 out of 13 patients, the position and size of the normal parathyroid gland as well as
parathyroid lesions were adequately demonstrated on ultrasound. One patient had ectopic
parathyroid adenoma which was confirmed on scintigraphy and excisional biopsy. Two patients
had normal appearing parathyroid gland which turned out to be adenomatous on histology. One
patient had indeterminate histology of an otherwise hypoechoic parathyroid region reported as
adenoma on ultrasound. Remaining 9 patients had large parathyroid adenomas initially picked on
ultrasound and later on confirmed on histology through US guided FNA. None of the patients had
concomitant thyroid disease or involvement of more than one parathyroid gland. All patients had
serum calcium of more than 11mg/dL and elevated serum PTH. On histopathology of FNA,
predominant cell type was chief cells arranged in sheets and occasionally small follicles with
variably thick connective tissue capsule. Cells with a clearer cystoplasm and occasionally
oncocytic cells were also seen.
Conclusion: High resolution ultrasound is a preliminary but sensitive investigation in detecting
parathyroid adenomas. When combined with US guided FNA, it becomes a highly specific and
accurate modality for preoperative identification and localization of parathyroid adenoma. We
highly recommend ultrasound for surgical road mapping of adenomas