Clinical characteristics of frequently recurring painless thyroiditis: contributions of higher thyroid hormone levels, younger onset, male gender, presence of thyroid autoantibody and absence of goiter to repeated recurrence.

Painless thyroiditis is characterized by transient thyrotoxicosis with complete recovery. Some patients, however, have repeated episodes of thyrotoxicosis, for which the mechanism of recurrence is not clear. We therefore studied the clinical characteristics in 8 patients with 4 or more episodes of thyrotoxicosis and 40 control patients. The age at onset was significantly earlier and the male-to-female ratio was significantly higher in the case group than the control group. The highest FT4 and FT3 levels were higher in the recurrent type. Multiple regression analysis showed contributions of higher peak FT4 level, male gender, presence of thyroid autoantibody, earlier onset, and smaller size of thyroid to repeated recurrence. Since the peak FT4 value, gender, autoantibody, age of onset and size of thyroid contribute to only 27.5% of the repeated recurrence cases, other factors such as genetic susceptibility or inflammatory tissue changes in thyroid may also be contributory. Further studies are needed to elucidate the mechanism underlying repeated recurrence.

Symptomatic hypercalcemia due to painless thyroiditis after unilateral adrenalectomy in a patient with Cushing's syndrome.

We report a 53-year-old woman with Cushing's syndrome due to an adrenocortical adenoma, who underwent unilateral adrenalectomy and developed symptomatic hypercalcemia during the thyrotoxic period of painless thyroiditis, while tapering off a daily supplemented dose of cortisol. A study of patients with thyrotoxicosis and hypoadrenalism at our institute revealed that mild hypercalcemia was present in 9.9% of those with thyrotoxicosis and 5.0% of those with hypoadrenalism. The present case suggests that the simultaneous occurrence of thyrotoxicosis and hypoadrenalism may lead to overt hypercalcemia due to a synergistic increase in bone resorption and impaired urinary excretion of calcium.

A juvenile case of Cushing's disease incidentally discovered with multiple bone fractures.

A 19-year-old woman who had decreased eight centimeters in stature was diagnosed as Cushing's disease with multiple spine compression fractures. At the age of 18, the patient had a complex fracture and gradually presented the features of Cushing's syndrome. Her plasma ACTH and cortisol levels were extremely high. Radiological findings and chemical markers for bone metabolism showed severe osteoporosis. Magnetic resonance imaging showed the presence of a pituitary microadenoma. After transsphenoidal surgery was performed, subsequently all endocrine data improved. This case indicates that Cushing's syndrome should be considered for severe osteoporotic juvenile patients.