Sonographic Differentiation of Thyroid Nodules With Eggshell Calcifications

Abstract

Objective. The purpose of this study was to assess the role of known suspicious sonographic findings and to find other additional sonographic findings to differentiate benign and malignant thyroid nodules with "eggshell" calcifications. Methods. Our Institutional Review Board approved this retrospective study, and informed consent was not required. We reviewed sonographic findings of thyroid nodules in 795 patients who underwent thyroid surgery in our institution between August 2006 and February 2007. Ninety-three thyroid nodules with eggshell calcifications in 92 patients were included in this study. Each lesion was evaluated for known suspicious sonographic criteria, including marked hypoechogenicity, irregular or microlobulated margins, and a taller-than-wide shape, as well as 2 additional sonographic findings: a hypoechoic halo and disruption of eggshell calcifications (halo and disrupted calcification rim). The sensitivity and specificity based on the sonographic criteria were calculated and compared among the 2 types of criteria. Results. Among the 93 thyroid nodules, 59 were malignant and 34 were benign. The halo and disrupted calcification rim showed higher sensitivity (62.7% and 76.3%, respectively) than any of the known suspicious sonographic criteria (40.7%, 35.6%, and 55.9%). The combination of both the halo and the disrupted calcification rim showed significantly higher sensitivity (93.2%) than the combination of the known suspicious sonographic criteria (78%; P < .05), although both had the same specificity (64.7%). Conclusions. In thyroid nodules with eggshell calcifications but no other calcifications, the findings of a peripheral halo and disruption of the eggshell calcifications may be more useful sonographic predictors of malignancy than hypo echogenicity, microlobulated margins, and a taller-than-wide shape.

Evaluation of cytopathological findings in thyroid nodules with macrocalcification: macrocalcification is not innocent as it seems

“…Previously, peripheral calcification was thought to occur secondary to chronic degenerative changes and therefore indicate a benign status. However, recent studies have found that macrocalcifications including peripheral calcification might also be an indicator of thyroid nodule malignancy (9,10,(16)(17)(18)24,25). In this study, we showed that cytologically malignant and suspicious for malignancy results are observed more frequently in nodules with parenchymal macrocalcification.…”

“…In previous studies, histopathologically proven malignancy rate of thyroid nodules with peripheral macrocalcification was reported to range between 18.5% to 70% with most of studies showing higher than 50% malignancy rate in these nodules (8)(9)(10)23). Majority of carcinomas were papillary type, with a few follicular carcinoma histopathologically.…”

“…Recent studies have revealed a relationship between macrocalcification and malignancy, particularly in papillary thyroid carcinomas (9,10,(16)(17)(18). In addition, despite the general belief that peripheral macrocalcification indicates benign situations, it was shown that if it is irregular it can also be related with malignancy (8,19).…”

“…Although, microcalcifications are known to be strongly associated with malignant nodules, the association of macrocalcifications with malignancy is controversial (8)(9)(10)(11)(12)(13)(14)(15). Recent studies have revealed a relationship between macrocalcification and malignancy, particularly in papillary thyroid carcinomas (9,10,(16)(17)(18).…”

Thyroid nodules and evaluation of thyroid cancer risk

“…They can be difficult to distinguish from colloid but the presence of comet‐tail artifacts associated with colloid crystals may be helpful 2 , 13 . The association of macrocalcifications with thyroid cancer is less consistent 8 , 11 , 12 , 15 . However, recent data suggest that coarse calcifications and disrupted peripheral or “eggshell” calcifications are also markers of increased cancer risk 4 , 11 , 12 .…”