Endocrine Abstracts

Introduction: The incidence of parathyroid carcinoma in primary hyperparathyroidism is less than 1% and the association with ACTH-independent Cushing syndrome is very rare.

Case report: A 40-year-old female was admitted for weight gain and reddish-purple striae. One month earlier she had a ¾ parathyroidectomy for primary hyperparathyroidism with histopathological examination showing a parathyroid carcinoma and two parathyroid adenomas. She also had a history of deep vein thrombosis. She had no family history of endocrinopathies. The physical exam revealed a positive Chvostek sign, facio-troncular obesity, reddish-purple striae and grade I hypertension. Biochemical assessment revealed hypocalcaemia (5.75 mg/dl) and diabetes mellitus. Hormonal assessment revealed hypoparathyroidism (PTH=12.45 pg/ml), no catecholamine excess, normal prolactin level. High levels of urine free cortisol (415.91 μg/dl) and positive long low dose DST(2mg/day×2 days) (12.29 μg/dl) confirmed the clinical suspicion of Cushing syndrome. ACTH levels were suppressed. Chromogranin A levels were normal. We performed a pituitary MRI and a CT of the neck, thorax and abdomen that showed bilateral adrenal macronodular hyperplasia with no other suspicious masses including pituitary adenomas. DXA evaluation showed osteoporosis for which she later received bisphosphonate therapy. A bilateral adrenalectomy was performed and subsequent mineralocorticoid and glucocorticoid replacement therapy was initiated. Genetic test for MEN1 syndrome is pending. The hyperparathyroidism relapsed 18 months after the parathyroidectomy. Calcium levels remained in the high normal range during monitoring with normal renal function and the last scintigraphy and CT scan showed an adenoma of the remaining parathyroid with no sign of local recurrence of the parathyroid carcinoma. Periodic follow-up also revealed a pituitary microadenoma with minimally raised prolactin and a thymic lesion that were stationary over the last 7 years of monitoring.

Conclusion: In patients with primary hyperparathyroidism special attention should be given to signs of other endocrinopathies as hyperparathyroidism could be the first manifestation of a MEN syndrome.