Primary Hyperparathyroidism Accompanied By Recovery Of Parathyroid Blood Flow Three Months After Spontaneous Parathyroid Hemorrhage

ABSTRACT Objective The objective of this report was to describe an unusual case of emerging primary hyperparathyroidism (PHPT) accompanied by recovery of parathyroid blood flow 3 months after spontaneous parathyroid hemorrhage. Methods Neck images and laboratory tests including serum calcium and parathyroid hormone (PTH) were performed to evaluate parathyroid hemorrhage. Pathologic findings after parathyroidectomy are also presented. Results A 58-year-old woman developed acute onset of neck pain and swelling with ecchymosis. Computed tomography showed a right paratracheal hematoma-like lesion behind the thyroid. Ultrasound (US) of the neck revealed a round, hypoechoic nodule measuring 27 × 25 × 18 mm in the right lower thyroid pole without vascular flow. Blood tests showed a corrected calcium of 9.3 mg/dL (normal, 8.7 to 10.3 mg/dL), and intact PTH of 68 pg/mL (normal, 10 to 65 pg/mL). Intact PTH measurement in fine-needle aspirate of the lesion was 339 pg/mL, confirming parathyroid origin. Repeat US after 3 months showed a remarkable decrease in lesion size with significant blood flow. Blood biochemistry showed a corrected calcium of 10.9 mg/dL, and an intact PTH of 237 pg/mL. She eventually underwent parathyroidectomy, and pathologic examination revealed parathyroid adenoma with a tiny thrombus. Conclusion Spontaneous remission of PHPT after parathyroid hemorrhage has been known to occur sporadically, a phenomenon referred to as autoparathyroidectomy. Although spontaneous remission with permanent improvement of PHPT may be observed, PHPT can recur in the relative short term after parathyroid hemorrhage, and so follow-up blood biochemistry surveillance is necessary. Also, evaluating parathyroid blood flow using color Doppler US might be useful in verifying the recurrence of PHPT. Abbreviations PHPT primary hyperparathyroidism PTH parathyroid hormone US ultrasound