[Hoffmann syndrome presenting to the emergency department].

We report a case of hypothyroid myopathy, or Hoffmann syndrome, in a 31-year-old man who presented to the emergency department with asthenia, muscular pain, cramps, and joint pain. Tests revealed increased creatine phosphokinase level (8102 U/L) and severe hypothyroidism (content of T4=3.8 pg/ml, T3=1.3 pg/ml, and thyrotropin stimulating hormone>150 microU/ml). Other causes of myopathy were excluded by anamnestic investigation and paraclinical exam. Treatment was begun with thyroid hormones (from 75 to 175 microg) and good clinical evolution was rapid. The pathophysiology of hypothyroid myopathy, clinical aspects and pathologic anatomic elements are described. The exact etiology of hypothyroidism must be known because some pathologic features are benign and treatment can have good results, whereas others, such as cancer, have worse prognosis.