title: Parathyroid incidentalomas detected during thyroid ultrasonography and effect of chronic thyroiditis on false positive parathyroid lesions.
abstract: We aimed to determine the prevalence of parathyroid incidentalomas in patients referred for thyroid ultrasonography (US) and investigate the role of chronic thyroiditis on false positive lesions. Patients suspected to have parathyroid lesions during thyroid US were recorded prospectively between August 2009 and January 2010. Patients referred for parathyroid US and patients with known high serum calcium or parathyroid hormone (PTH) levels were excluded. Suspected parathyroid lesions were defined as hypoechoic, homogeneous, solid lesions with regular margins located outside the thyroid lobe, most commonly inferior to the thyroid gland. Thyroid US was performed in 6,528 patients. There were 78 patients (1.19 %) (73 female and 5 male) with suspected parathyroid lesion. The diagnosis of a true parathyroid adenoma was confirmed in 6 (7.69 %) patients. In patients with true adenoma, mean serum calcium, phosphorus, and PTH levels were 10.57 ± 0.48 mg/dl, 3.03 ± 0.52 mg/dl, and 182.91 ± 46.62 pg/ml, respectively. Among 72 patients with false positive parathyroid lesion, antithyroid peroxidase antibody was positive in 50 (69.4 %), antithyroglobulin antibody was positive in 46 (63.9 %), and one of these antibodies were positive in 59 (81.9 %) patients. Also, 46 (63.9 %) of these patients had thyroid dysfunctions (43 hypothyroidism and 3 hyperthyroidism) and 59 (81.9 %) had chronic thyroiditis ultrasonographically. Parathyroid incidentaloma was detected in 0.09 % of patients referred for thyroid US. The presence of clinically or ultrasonographically chronic thyroiditis might cause inadvertent interpretation of a hypoechoic lesion as a parathyroid pathology during thyroid US.
authors.affiliation: Department of Endocrinology and Metabolism, Ataturk Education and Research Hospital, Yıldırım Beyazit University, Ankara, Turkey. sendidem2002@yahoo.com
authors.forename: Didem
authors.initials: D
authors.lastname: Ozdemir
authors.forename: Dilek
authors.initials: D
authors.lastname: Arpaci
authors.forename: Rifki
authors.initials: R
authors.lastname: Ucler
authors.forename: Neslihan
authors.initials: N
authors.lastname: Cuhaci
authors.forename: Reyhan
authors.initials: R
authors.lastname: Ersoy
authors.forename: Bekir
authors.initials: B
authors.lastname: Cakir
mesh_terms: D000236:Adenoma / Q000150:complications / Q000000981:diagnostic imaging*; D000328:Adult; D000368:Aged; D002908:Chronic Disease; D005189:False Positive Reactions; D005260:Female; D006801:Humans; D007453:Iodide Peroxidase / Q000276:immunology; D049449:Luminescence; D008297:Male; D008875:Middle Aged; D010281:Parathyroid Hormone / Q000097:blood; D010282:Parathyroid Neoplasms / Q000150:complications / Q000000981:diagnostic imaging*; D011446:Prospective Studies; D013954:Thyroglobulin / Q000032:analysis / Q000276:immunology; D013961:Thyroid Gland / Q000000981:diagnostic imaging*; D013966:Thyroiditis / Q000150:complications / Q000000981:diagnostic imaging*; D014463:Ultrasonography
chemical_list: D010281:Parathyroid Hormone; D013954:Thyroglobulin; D007453:Iodide Peroxidase