OBJECTIVE: We report a very rare case of Hoffmann's syndrome with 
musclehypertrophy complicating hypothyroidism.
CLINICAL PRESENTATION: A 24-year-old man presented with a 2-year history of 
forgetfulness, swelling in his face, shoulder and calf, and motor weakness in 
his lower extremities. His calf and shoulder muscles were hypertrophic. 
Neurological examination revealed hoarseness of the voice, proximal muscle 
weakness, reduced deep tendon reflexes and a mildly ataxic gait. Laboratory 
tests indicated markedly elevated serum muscle enzymes and lipids, a high 
thyroid-stimulating hormone level and low free triiodothyronine and free 
thyroxine levels. Electromyographic evaluation showed myopathy.
INTERVENTION: Oral L-thyroxine treatment was started and at a 1-month follow-up 
examination, mental status and physical performance were improved.
CONCLUSION: This report shows that in the differential diagnosis of myopathy 
with pseudohypertrophy, Hoffmann's syndrome should be considered.