MED10 Spontaneous remission of primary hyperparathyroidism due to autoinfarction/hemorrhage of a parathyroid adenoma. (Medicine).

MED10 SPONTANEOUS REMISSION OF PRIMARY HYPERPARATHYROIDISM DUE TO AUTOINFARCTION/HEMORRHAGE OF A PARATHYROID ADENOMA. John T. Kolisnyk, DO, and Maureen K. Koops, MD. Brooke Army Medical Center, Fort Sam Houston, Tex.

Primary hyperparathyroidism (PHPT) is a common endocrine disorder usually caused by a parathyroid adenoma. PHPT typically presents as asymptomatic hypercalcemia discovered on routine laboratory testing. Many patients can be followed medically, but surgical therapy is often required. We report a case of PHPT associated with spontaneous remission due to autoinfarction or hemorrhage of a parathyroid adenoma. The patient is a 50-year-old woman who was noted to have persistently elevated serum calcium (Ca) levels 10.4 to 10.8 mg/dL (normal, 8.8 to 10.4 mg/dL) and low serum phosphate ([PO.sub.4]) levels 2.0 to 2.2 mg/dL (normal, 2.5 to 4.3 mg/dL) on routine laboratory testing. 24-hour urine Ca was 182.3 mg. Parathyroid hormone (PTI-I) levels were elevated at 87.8 to 117 pg/mL (10 to 65 pg/mL), consistent with primary hyperparathyroidism. A parathyroid scan showed a left lower parathyroid adenoma. The patient had no complications from her mild hypercalcemia for more than a year. After a physical examination of her n eck during a routine appointment, she had acute onset of severe left neck pain with nausea and vomiting. Several hours later, tingling and painful muscle cramps developed in the extremities. The serum Ca was low at 8.7 mg/dL; the serum [PO.sub.4] was normal at 3.5 mg/dL and the PTH level was now normal at 30.0 pg/mL. A repeat 24 hour urine Ca was 92.4 mg. Follow-up parathyroid scan showed no evidence of the previously identified parathyroid adenoma. An MRI of the neck revealed a 1 cm area of hemorrhage in the area of the left parathyroid adenoma with adjacent edema. The patient's symptoms resolved with supplemental Ca and vitamin D. Within 2 weeks, her serum Ca normalized and she was able to stop her supplemental Ca and vitamin D. Her serum Ca, PO4 and PTH levels have remained normal for more than a year. Spontaneous remission of PHPT by autoinfarction or hemorrhage of a parathyroid adenoma is rare; fewer than 30 cases have been reported. The cause of the infarction or hemorrhage in this case and others in th e literature remains unknown. Spontaneous autoinfarction or hemorrhage may rarely result in resolution of PHPT.