MON-256 Co-Occurrence of Parathyroid and Corticotroph Adenoma in a Pediatric Patient without MEN1

Introduction: We report a pediatric case of primary hyperparathyroidism due to a parathyroid adenoma and Cushing’s disease due to a pituitary adenoma. Clinical Case: The patient presented at 13.5 years old for hypertension that was discovered during an exam for weight loss, headaches, and paresthesias. Evaluation was significant for elevated blood pressure (148/98 mmHg), obesity (BMI 96.5%), striae, and he was found to be midpubertal. Tests showed calcium levels 10.7 (RR 8.6-10.6 mg/dL), aldosterone 2.4 (RR 4.0-31.0), and 24 hour urine cortisol/creatinine 451 ug/g (prepubertal RR< 25, >18 yo <32 ug/g). Renin, urine metanephrines and normetanephrine, TSH, and free T4 were all unremarkable. MRI and CT showed absence of the septum pellucidum and mild cortical atrophy. PTH was 76.6 pg (calcium 11.4). Subsequent sestamibi scan showed a solitary parathyroid adenoma. Family history was negative for endocrinopathy. MEN1 sequencing, prolactin, gastrin, and VIP levels were normal. Minimally invasive parathyroid adenomectomy was performed 3 months post-presentation with normalization of calcium and PTH and improved blood pressures. The patient was then lost to endocrinology follow up until 18.5 years of age. In the interval, he continued to have persistent hypertension despite antihypertensive medication and normal PTH and calcium levels. Exam at this time showed a blood pressure of 137/98 mmHg, obesity with BMI of 29.8 kg/m2, and increased abdominal striae. Tests showed AM cortisol of 39.1 ug/dL, ACTH of 85 (RR 6-55 pg/mL), and 24 hour urine cortisol/creatinine of 1306 ug/g. MRI showed a 7 mm hypo-enhancing lesion in the left pituitary. Follow-up MRI of the brain with contrast revealed a 7 mm pituitary adenoma. Inferior petrosal sinus sampling showed peak ACTH levels of 10869 pg/mL (left) and 2738 pg/mL (right). RET analysis and neurosurgical pituitary adenomectomy are planned. Conclusion: Co-occurrence of a pituitary corticotroph and parathyroid adenoma without MEN1 mutation is rare and, to our knowledge has not been reported in a pediatric patient.