October 11, 1976

Metastatic Occult Follicular Thyroid Carcinoma

Author Affiliations

Newton-Wellesley Hospital Newton Lower Falls, Mass

JAMA. 1976;236(15):1693. doi:10.1001/jama.1976.03270160017016

To the Editor.—  The case of metastatic occult follicular thyroid carcinoma reported by Boehm et al (235:2420,1976) is a rare exception to the good general rule that occult thyroid carcinomas are harmless tumors. In addition to the present case and the two others cited by the authors, I know of two cases of occult thyroid carcinoma that have metastasized beyond the local cervical nodes. Both were fatal cases reported in large series by Hazard1 and ourselves.2Occult thyroid carcinomas are present in 5.7% to 13%3,4 of recent American autopsy series and in up to 28% of Japanese and Japanese-American autopsy series.2,5 Since there is no increase in the prevalence of these tumors with age and since they almost never cause death, an autopsy series is a good estimate of their frequency in the general population. Using these estimates, there should be small occult thyroid carcinomas in