METHODS: A 17-year-old female patient was referred to our outpatient clinic due to menstrual irregularities. She had muscle pain and multiple cystic ovaries in addition to clinical signs of severe congenital hypothyroidism. High levels of creatinine and creatinine kinase and accompanying muscle hypertrophy were present. After the initiation of L-thyroxine therapy, the symptoms were alleviated in a short time.
CONCLUSIONS: Congenital and acquired hypothyroidism should be considered in the differential diagnosis of pseudo-precocious puberty and myopathy that presents with muscle pain, muscle hypertrophy, and elevated creatinine kinase levels.