Cytopathologist‐performed ultrasound‐guided fine‐needle aspiration of parathyroid lesions

Abstract

The gold standard to determine the cause of primary hyperparathyroidism (PHPT) is bilateral neck exploration. As most cases are caused by parathyroid adenoma, there is a movement toward preoperative localization of the abnormal gland by ultrasound and/or Tc(99)-sestamibi scan and minimally invasive parathyroidectomy. Nonpalpable thyroid nodules are common and cannot be differentiated from parathyroid lesions by imaging alone. This study examines cytopathologist-performed ultrasound-guided fine-needle aspiration (UG-FNA) in diagnosis of parathyroid lesions. Between January 1, 2007 and December 31, 2008, seven patients with PHPT or other parathyroid lesions with one or more sonographically-visible thyroid masses underwent cytopathologist-performed UG-FNA with immediate cytological evaluation (ICE). One mass was palpable and nine were nonpalpable. Three parathyroid adenomas, two benign colloid nodules, one papillary carcinoma, three parathyroid cysts, and one thyroid cyst were diagnosed. The nodules in three patients with parathyroid adenomas were identified as follicular lesion/neoplasm on ICE. Additional UG-FNA passes were made to obtain tissue for immunohistochemistry stains, which confirmed parathyroid origin. Two of these patients had a separate benign colloid nodule and one had a thyroid cyst diagnosed by UG-FNA. The PHPT patient with papillary carcinoma on UG-FNA had the malignancy confirmed at surgery and a sonographically occult parathyroid adenoma. The three patients with thyroid cysts identified by radiology were suspected of being parathyroid cysts on the basis of real-time sonographic features at the biopsy table. The clear cyst fluid obtained by UG-FNA had markedly elevated PTH. Cytopathologist-performed UG-FNA can distinguish between parathyroid and thyroid nodules in patients with suspected parathyroid lesions.

Small nonfunctional parathyroid cysts: single institution experience

“…Study material was obtained by ultrasound-guided fine-needle aspiration biopsy (UG-FNA) performed by a clinical cytologist (interventional cytologist) [11], who also performed cytomorphological analysis of the material obtained.…”

“…Occasionally, it may be necessary to perform FNA of more than one suspect mass, frequently from several sites. Parathyroid cyst FNA generally yields clear, colorless, water-like or golden-brown fluid [1,2,7,11,13,[25][26][27]. Aspirate sediment should be examined on a microscope, along with determination of aspirate PTH.…”

Clinical Workup of Nodular and Mass Lesions of the Endocrine Organs

“…Some authors suggested that FNA is valuable in patients who have a nondiagnostic Tc 99 -sestamibi scan, with multiple enlarged parathyroid glands, prior failed surgery, differentiating parathyroid adenomas from posterior thyroid nodules, atypical location, and nonfunctioning parathyroid incidentalomas (Abraham, Duick et al 2008;Vu and Erickson 2010). Cellular FNA specimens with features not typical for thyroid lesions should be triaged for PTH assay in the FNA rinse, which is useful to differentiate parathyroid lesions from thyroid lesions (Owens, Rekhtman et al 2008;Ciuni, Ciuni et al 2010;Lieu 2010). This technique is also used during operation (Lamont, McCarty et al 2005).…”

“…The ultrasound images demonstrate a cystic lesion. FNA aspirates clear liquid, which should be sent to chemistry laboratory to test PTH level (Absher, Truong et al 2002;Ciuni, Ciuni et al 2010;Lieu 2010). The first treatment is the aspiration FNA, which can be curative, but recurrences can be treated surgically (Ciuni, Ciuni et al 2010).…”

“…The FNA cytomorphology of parathyroid adenoma shares some features with thyroid lesions, which may lead to misinterpretation as thyroid follicular lesion/neoplasm, medullary carcinoma, papillary carcinoma, and thyroid cyst (Absher, Truong et al 2002;Owens, Rekhtman et al 2008;Lieu 2010). Therefore, a PTH assay of needle rinse and IHC studies should be ordered for any case with an FNA cytomorphology that is not typical for thyroid lesion, PCS develop due to absence of colloid, and is a highly cellular specimen.…”