Calcifications in Thyroid Ultrasonography and Thyroid Carcinoma

Abstract

Background: Thyroid nodules are a common disease entity occurring in 5-10% of the general population and increasing with age. Their detection on ultrasonography ranges from 13% to 67%. Calcifications on ultrasound may occur in both benign and malignant diseases, but have been cited for increased risk of thyroid carcinoma. 
 Objective: To determine the association of calcifications found on thyroid ultrasonography and the different types of calcifications with thyroid carcinoma.
 Method:
 Study Design: Retrospective Study
 Setting: Tertiary Private Hospital
 Participants: 126 patients with pre-operative thyroid or neck ultrasonography who subsequently underwent thyroidectomy (total or subtotal, with or without frozen section) were selected from a database covering a one-year period from January to December 2012. The presence and type of calcification on ultrasonography was correlated with the final histopathologic report for a diagnosis of thyroid carcinoma. Sensitivity, specificity, positive and negative predictive values were obtained.
 Results: 51 out of 126 studies (40%) were observed to have calcifications of any description, in both histologically benign (41%) and malignant (59%) nodules. Calcifications seen in malignancy arose from papillary carcinoma (86%). Follicular carcinoma and others (Plasmacytoma and Lymphoma) accounted for 7% each. The peripheral type of calcification was most prevalent accounting for 37% (11 out of 30). The sensitivity of detecting calcifications on ultrasonography is 58.82%, specificity 81.33%, positive predictive value 68.18% and negative predictive value 74.38%. Chi square test computed was 21.54 (P <0.05).
 Conclusion: There was an association between calcification found on ultrasonography and thyroid carcinoma and 86% of the calcifications were peripheral patterns, mostly found in papillary thyroid carcinomas. Ultrasonography alone is not sufficient in diagnosing thyroid carcinoma, but may increase the suspicion of malignancy depending on the type of calcification.
 Keywords: Thyroid carcinoma, papillary carcinoma, calcifications, ultrasonography

Association of Ultrasonographic Findings and Thyroid Malignancy: A Cross-Sectional Study

“…Microcalcifications were noted to have strong association with malignancy. 1,2 In a study by Sio et al, 86% of papillary thyroid carcinoma cases displayed microcalcification on thyroid UTZ. 2 This feature had the highest accuracy (76%), specificity (44-95%), and predictive value (77.9%) in detecting malignancy.…”

“…1,2 In a study by Sio et al, 86% of papillary thyroid carcinoma cases displayed microcalcification on thyroid UTZ. 2 This feature had the highest accuracy (76%), specificity (44-95%), and predictive value (77.9%) in detecting malignancy. 1 These sonographic findings are consistent with hyperechoic foci with or without shadowing, corresponding histopathologically to psammoma body clusters.…”

“…1 Though most palpable nodules are benign, there is a 5-10% risk of having a malignancy. 2 The American Thyroid Association (ATA) strongly recommends thyroid ultrasonography (UTZ) for patients with suspected or incidentally-detected nodules. This modality is able to determine the presence of suspicious nodules, their character and location, and guide the accuracy of Fine Needle Aspiration Biopsy.…”

“…3 A number of studies have been published associating specific sonographic findings with thyroid malignancy. 1,2,[4][5][6][7][8][9] Many elucidate the role of nodule size and presence of microcalcifications. 2,[4][5][6][7][8][9] The ATA listed presence of disrupted rim calcifications with small extrusive hypoechoic soft tissue component, evidence of extrathyroidal extension, nodule shape and features as determinants of malignancy.…”