Hoffmann's syndrome and pituitary hyperplasia in an adolescent secondary to Hashimoto thyroiditis.

BACKGROUND

Diffuse muscle hypertrophy is a rare complication of acquired hypothyroidism. When accompanied by stiffness, weakness, and painful muscle cramps, the condition is known as Hoffmann's syndrome (HS). HS is usually seen in young adults due to long-standing untreated primary hypothyroidism. We report a very rare case of HS with muscle hypertrophy and pituitary hyperplasia complicating hypothyroidism in an adolescent.

CASE: A 12-year-old male admitted with muscle pain, headache, and fatigue. He had marked hypertrophy of both calf and shoulder muscles. Laboratory tests indicated elevated muscle enzymes and lipids with an elevated thyrotropin and low thyroxine levels. Hashimoto thyroiditis was confirmed on thyroid studies. He had also papilledema bilaterally and magnetic resonance imaging showed an enlargement of the pituitary gland. Treatment with thyroid hormone resulted in complete improvement of symptoms within 3 months.

CONCLUSIONS

HS is a rare but treatable form of acquired myopathies and can be seen in children due to untreated hypothyroidism. All patients with an acquired myopathy and muscular pseudohypertrophy should be screened regarding thyroid hormones.