Article révisé par les pairs
Résumé : The ultrastructure of the thyroid gland in a case of female myxedema appears to be similar to that of chronic autoimmune thyroiditis. Only a few follicles are present, and most of their cells show an oncocytic transformation. A new thyroid cellular type characterized by numerous cytoplasmic fibrils recalls the appearance of some cells described in the so called ultimobranchial follicles of the rat's thyroid.