[Thyroid cancer and pregnancy]

Thyroid cancer is very rare during pregnancy, but a thyroid nodule is more likely to be cancerous if discovered during pregnancy (43 p. cent versus 15 p. cent). The diagnosis is more difficult. Tests using radioactive substances are contraindicated during pregnancy. Ultrasonography does not permit to specify the nature of the nodule and aspiration biopsy with cytological examination becomes the examination of choice. One should not hesitate to operate on these nodules, during pregnancy, if the diagnosis is made. It is difficult to assert that the prognosis is aggravated by pregnancy since there are so few cases, but several authors report a few cases with an abnormally fast progression during pregnancy. Forms which are properly treated and occurred before the age of 40, are not a contraindication to subsequent pregnancies, if they are not anaplastic or metastatic forms. However, a reasonable delay of the surgery is advised in order to stabilize the hormonal treatment and the calcium-phosphorus balance.