Endocrine Abstracts

Introduction: Multiple endocrine neoplasia type 1 (MEN-1) is a rare, autosomal dominant inherited disorder, characterized by a high predisposition to develop a wide spectrum of endocrine and nonendocrine tumors, mostly of parathyroids, endocrine pancreas, and anterior pituitary.

Methods: Analysis of clinical and laboratory data, family history of multiple endocrine neoplasia.

Results: A 19-year-old woman with autoimmune thyroiditis and hypothyroidism was routinely examined in outpatient Endocrine Department in Minsk (Belarus). Replacement therapy with levothyroxine 50 mg was prescribed 2 yrs ago. She complained sickness, in the anamnesis–eating behavior disorders with body mass fluctuations during last year. Occasionally low levels of serum potassium were revealed and she was hospitalized in Medical Academy Clinic. It appeared that her mother had pituitary macroadenoma (somatotropinoma) and primary hyperparathyroidism with hypercalcemia, verified in 2019 yr. She was prescribed aledronic acid medication to control the levels of serum calcium. Parathyroid surgery was postponed because of unclear reason. Mother’s sibling and nephews are living in Germany and MEN-1 mutation was verified in their family. Their MEN-1 phenotype was characterized by primary hyperparathyroidism, pituitary adenoma. Pancreas tumor was diagnosed in one family member 48 years old. New anamnesis data influenced the diagnostic protocol in our patient - increased levels of PTH were diagnosed (255.0 ng/l, reference range, 10–65 ng/l). Routine biochemistry revealed near normal Calcium level of 1.35 mmol/l (reference range, 1.12–1.32 mmol/l). She had no symptoms of hypercalcemia. Parathyroid scintigraphy was normal. Serum potassium levels became near normal on infusion therapy (3.9 mmol/l). Screening for parathyroid, pancreas endocrine tumors and pituitary adenoma started.

Conclusion: Primary hyperparathyroidism is the most frequent and usually the earliest expression of MEN-1, with typical age of onset at 20–25 years. Early detection of the disease and correct treatment are therefore of great importance. Education of members of families with MEN-1 is worth doing as well as molecular screening for MEN-1 mutation to individualized their diagnostic and treatment protocols.