I agree with Rosario’s comment that ultrasonographic examination of the thyroid can provide additional evidence of thyroid autoimmunity. However, this examination is associated with a risk of incidental findings. A large proportion of diagnoses of thyroid cancer in the past two decades were probably due to diagnostic changes after the introduction of ultrasonographic examination of the neck in the 1980s. This is best illustrated by data from South Korea, where a large-scale introduction of ultrasonographic examination of the thyroid (ultrasonographic examination of the neck was offered at a low cost in addition to organized screening programs for other cancers) resulted in a rate of thyroid-cancer diagnoses in 2011 that was 15 times that observed in 1993.3 Despite this dramatic increase in incidence, thyroid cancer–specific mortality remained stable; this clearly suggests overdiagnosis of indolent thyroid cancers.
It is estimated that overdiagnosis accounts for the majority of cases of thyroid cancer in many Western countries.4 In the context of guidelines from professional societies that emphasize avoidance of both overdiagnosis and overtreatment of thyroid cancer,5 ultrasonographic examination of the neck should not be performed routinely in the management of subclinical hypothyroidism unless there are additional clinical indications.

Additional Metadata
Persistent URL dx.doi.org/10.1056/NEJMc1709853, hdl.handle.net/1765/102263
Journal New England Journal of Medicine
Note

Original article: http://www.nejm.org/doi/full/10.1056/NEJMcp1611144

Citation
Peeters, R.P. (2017). The author replies [Subclinical Hypothyroidism]. New England Journal of Medicine, 377(14). doi:10.1056/NEJMc1709853