Remission of Primary Hyperparathyroidism Following Fine-Needle Aspiration Biopsy: A Case Report and Review of the Literature

Background

Spontaneous or fine-needle aspiration biopsy (FNAB)-induced remission of primary hyperparathyroidism (PHPT) is an extremely rare and generally transient phenomenon.

Methods

A 40-year-old woman with a history of recurrent kidney stones was diagnosed with PHPT (serum calcium, 14.2 mg/dL; parathyroid hormone [PTH], 380 pg/mL). Ultrasonography and scintigraphy findings were consistent with a left enlarged parathyroid. Ultrasound-guided-FNAB cytology of the lesion did not confirm a parathyroid nature. However, levels of PTH within the needle-washing fluid were elevated.

Results

After few days, there was evidence of biochemical remission of the hypercalcemia (calcium, 8.1 mg/dL), and at subsequent follow-up visits, the enlarged parathyroid showed progressive shrinkage with eucalcemia and normalized PTH levels throughout 12 months of follow-up.

Conclusions

Rarely, remission of PHPT may occur after ultrasound-guided-FNAB performed on a hyperfunctioning parathyroid lesion.

PRIMARY HYPERPARATHYROIDISM ACCOMPANIED BY RECOVERY OF PARATHYROID BLOOD FLOW THREE MONTHS AFTER SPONTANEOUS PARATHYROID HEMORRHAGE

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.