Endocrine Abstracts

Introduction: The simultaneous occurrence of central hyperthyroidism and primary hyperparathyroidism is extremely rare. Few cases of TSH pituitary adenoma in the setting of multiple endocrine neoplasia type 1-associated syndrome were reported in literature. Herein, we report a new case of TSH secreting pituitary adenoma particular by the coexisting of primary hyperparathyroidism and vitamin D deficiency.

Observation: A 76-year-old woman was referred to our Department with thyrotoxicosis and elevated TSH levels. She presented with an important weight loss, intolerance to heat, restlessness, flapping tremor, diarrhea and vomiting. On examination, she had a body mass index of 19 kg/m², a clinical signs of dehydration, a blood pressure of 120/60 mmHg and an irregular pulse of 120 beats/min. Thyroid gland was asymmetrically enlarged. No proptosis was observed. Electrocardiogram showed an arythmic tachycardia (120/min). Echocardiography revealed moderate, asymmetric hypertrophy of the left ventricle. Systolic and diastolic functions were preserved. Laboratory tests revealed central hyperthyroidism and primary hyperparathyroidism. The 25 OH vitamin D was 4.6 μg/l (nr: 30–100 μg/l). Serum creatinine was 131 μmol/l and creatinine clearance was 59 ml/min. Pituitary hormone explorations revealed hypogonadotropic hypogonadism with normal lactotropin and corticotropin functions. Pituitary MRI scan showed an invasive pituitary adenoma measuring 21×15×17 mm and causing right cavernous sinus invasion. Sestamibi parathyroid scintigraphy, cervical and thoracic magnetic resonance imaging were normal. Bone densitometry revealed osteopenia. The patient was symptomatically treated with intravenous fluid replacement therapy, antithyroid drugs and beta blockers. Due to the patient’s poor general condition, surgical approach of the TSH-oma was contraindicated and pituitary radiotherapy was considered.

Conclusion: Although vitamin D deficiency and primary hyperparathyroidism are common disorders in the elderly population, their association to TSH pituitary adenoma is a rare condition.