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

Abstract

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.

Dysregulation of calcium metabolism in type 1 myotonic dystrophy

“…5 Hypercalcaemia secondary to the primary hyperparathyroidism (PHPT) has been anecdotally reported, [6][7][8] with a recent literature review noting 34 reports of isolated PHPT due mainly to parathyroid adenomas. 9 The authors of this review suggested that PHPT may be more prevalent in patients with DM1 than previously recognised. In addition, it is noted that very few studies describe the nature of dysregulated calcium metabolism in such cases and its effects on bone health.…”

“…Endocrine and metabolic disorders in DM1 include the metabolic syndrome, impaired glucose handling, dyslipidaemia, primary hypogonadism and adrenocortical secretory insufficiency . Hypercalcaemia secondary to the primary hyperparathyroidism (PHPT) has been anecdotally reported, with a recent literature review noting 34 reports of isolated PHPT due mainly to parathyroid adenomas . The authors of this review suggested that PHPT may be more prevalent in patients with DM1 than previously recognised.…”

Autoimmune polyglandular disorders in myotonic dystrophy

“…Пациентка страдала двусторонней катарактой. Лабораторные исследования выявили высокие уровни кальция, фосфора и паратгормона в сыворотке, сниженную концентрацию ТТГ и отсутствие АТ к тиреопероксидазе [14].…”

Case Report and Literature Review of an Atypical Polymyalgia Rheumatica and Its Management

“…20,[30][31][32][33][34][35] ESR and CRP levels were found to be markedly elevated in this patient and were monitored during follow-ups (Table 1). Other laboratory tests that are supportive of suspected PMR and the exclusion of other disorders include assessment of the thyroid-stimulating hormone, 36 electrolytes, alkaline phosphatase levels, creatinine, and creatine phosphokinases. [37][38][39][40][41][42] All of these were normal in this patient (Table 1).…”