Frequency of hypothyroidism after subacute thyroiditis and contribution ofultrasonographic thyroid volume measurement.

Subacute thyroiditis conventionally recovers without aftereffect, Neverthel ess some data relate a 5 to 9% occurence of final hypothyroidism 6 months a fter the acute stage, We herein studied end-stage hypothyroidism occurrence and effect of thyroid volume alterations on hormonal course during thyroid itis. Twenty-nine cases of subacute thyroiditis were studied, Final thyroid funct ion remained normal in 15 patients (51%) and undetermined in 5 patients (17 %), Final hypothyroidism (TSH: 4.5-14.5 muU/mL) occurred in 9 patients (31% ), Mean thyroid volume was increased in acute stage in patients with final normal thyroid function (16.6 +/-5.7cm(3)) and decreased by 63% during foll ow-up; final mean thyroid volume was 6.1 +/-1.3cm(3), Mean thyroid volume w as normal in acute stage in final hypothyroid patients (10.7 +/-3.0cm(3)) a nd decreased by 72% during follow-up; final mean thyroid volume was 3.3 +/- 1.1cm(3). End-stage mean thyroid volume was significantly Lower in final hy pothyroid patients (p <0.05) compared to patients with final normal thyroid function, We conclude that the occurrence of final hypothyroidism is underestimated a fter subacute thyroiditis, Ultrasonographic follow-up might be helpful in t he detection of final hypothyroid-risk patients: thyroid volume not increas ed in acute stage and Lower than 5cm(3) during follow-up is one of the ultr asonographic features of these patients.