Primary Hyperparathyroidism and Hyperthyroidism in a Patient with Myotonic Dystrophy: A Case Report and Review of the Literature

Abstract EN

Various endocrine manifestations are commonly described in myotonic dystrophy (MD), including primary hypogonadism, diabetes mellitus, and thyroid and parathyroid dysfunction.

We describe a 46-year-old woman with a family history of MD with her son.

She was diagnosed with cardiac arrhythmia and required the implantation of a pacemaker.

She was noted to have a bilateral cataract.

She complained of muscle weakness, diffuse myalgia, and palpitation.

The electromyography (EMG) showed myotonic discharges.

Laboratory tests showed high serum calcium 2.83 mmol/L, serum phosphate 1.2 mmol/L, parathormone 362.5 pg/mL, thyroid stimulating hormone TSH 0.02 mIU/L (normal range: 0.34–5.6 mIU/L), FT4 21.17 ng/mL, and negative anti-thyroperoxidase antibodies.

Cervical ultrasound revealed a multinodular goiter.

The 99mTc-MIBI scintigraphy localized a lower right parathyroid adenoma.

The clinical data, the family history of MD, EMG data, and endocrine disturbances were strongly suggestive of MD associated with hyperthyroidism and primary hyperparathyroidism.