Euthyroid pretibial myxedema

To describe a case of biopsy-proven pretibial myxedema in a man with normal thyroid function.

We present the pertinent clinical and laboratory data for the current case and review previously published information on pretibial myxedema.

Our patient, a 53-year-old man, had the characteristic lesions of pretibial myxedema on the anterolateral aspects of his calves. Laboratory tests showed normal thyroid function. The thyroid-stimulating immunoglobulin value was above normal. No exophthalmos or goiter was present. This uncommon dermopathy is typically associated with Graves' disease, accompanied by clinical hyperthyroidism, ophthalmopathy, and goiter.

The pathogenesis of pretibial myxedema remains elusive. It is presumed to be an autoimmune phenomenon attributable to the presence of serum thyroid-stimulating immunoglobulin, although immunofluorescence studies have failed to demonstrate a direct role for such an immunoglobulin. Only two other cases of biopsy-proven pretibial myxedema in a euthyroid patient were found in the literature.