Primary hyperparathyroidism due to atypical vertically long cystic adenoma.
Parathyroid cystic adenomas are often misdiagnosed as thyroid cysts and routine preoperative diagnostic tools, such as ultrasonography (US) or 99m technetium-sestamibi (99mTc-MIBI) scans, cannot clearly distinguish between these entities. We present a 67-year-old hypercalcemic woman with a cervical cystic lesion who had negative sestamibi scan results. Her laboratory data indicated primary hyperparathyroidism (serum calcium concentration 14.0 mg/dl, phosphate concentration 2.3 mg/dl, and intact parathyroid hormone (PTH) concentration 239 pg/ml). The cervical US and computed tomography scans revealed a large and vertically long cystic mass (12×11×54 mm). A mass was located from the upper end of the left thyroid lobe to the submandibular region and was not clearly distinguishable from the thyroid. For preoperative definitive diagnosis, we carried out a parathyroid fine-needle aspiration (FNA) and PTH assay (PTH-FNA) of liquid aspirated from the cyst. The intact PTH-FNA concentration was 1.28×10(6) pg/ml, and the patient was diagnosed with primary hyperparathyroidism due to a cystic mass. She underwent a left upper parathyroidectomy and her serum calcium and intact PTH concentration immediately decreased to normal levels. This report describes the usefulness of PTH-FNA for localizing and differentiating an atypical functional parathyroid lesion from nonfunctional tissue in primary hyperparathyroidism.


CONCLUSIONS
Cystic parathyroid lesions, even in the case of elevated PTH levels, can produce negative results in 99mTc-MIBI scans.Preoperative diagnosis of parathyroid cysts detectable on US is possible by parathyroid FNA and PTH assay (PTH-FNA) of liquid aspirated from the cyst, if malignancy is not suspected. PTH-FNA could be helpful in the differential diagnosis of an equivocal cervical tumor.
Department of Endocrinology and Metabolism , National Hospital Organization Kyoto Medical Center , Kyoto , Japan ; Department of Diabetes , Endocrinology and Metabolism, Tango Central Hospital , Kyoto , Japan.
Sachiko-Tsukamoto
ST
Kawashima
Clinical Research Institute , National Hospital Organization Kyoto Medical Center , 1-1 Mukaihata-cho, Fukakusa, Fushimi-ku, Kyoto, 612-8555 , Japan.
Takeshi
T
Usui
Department of Endocrinology and Metabolism , National Hospital Organization Kyoto Medical Center , Kyoto , Japan.
Yohei
Y
Ueda
Department of Endocrinology and Metabolism , National Hospital Organization Kyoto Medical Center , Kyoto , Japan.
Maiko-Kakita
MK
Kobayashi
Department of Endocrinology and Metabolism , National Hospital Organization Kyoto Medical Center , Kyoto , Japan.
Mika
M
Tsuiki
Department of Endocrinology and Metabolism , National Hospital Organization Kyoto Medical Center , Kyoto , Japan.
Kanako
K
Tanase-Nakao
Department of Endocrinology and Metabolism , National Hospital Organization Kyoto Medical Center , Kyoto , Japan.
Kazutaka
K
Nanba
Department of Endocrinology and Metabolism , National Hospital Organization Kyoto Medical Center , Kyoto , Japan.
Tetsuya
T
Tagami
Clinical Research Institute , National Hospital Organization Kyoto Medical Center , 1-1 Mukaihata-cho, Fukakusa, Fushimi-ku, Kyoto, 612-8555 , Japan.
Mitsuhide
M
Naruse
Department of Head and Neck Surgery , National Hospital Organization Kyoto Medical Center , 1-1 Mukaihata-cho, Fukakusa, Fushimi-ku, Kyoto, 612-8555 , Japan.
Yoshiki
Y
Watanabe
Department of Head and Neck Surgery , National Hospital Organization Kyoto Medical Center , 1-1 Mukaihata-cho, Fukakusa, Fushimi-ku, Kyoto, 612-8555 , Japan.
Ryo
R
Asato
Osaka Saiseikai Ibaraki Hospital , Osaka , Japan.
Sumiko
S
Kato
Clinical Research Institute , National Hospital Organization Kyoto Medical Center , 1-1 Mukaihata-cho, Fukakusa, Fushimi-ku, Kyoto, 612-8555 , Japan.
Akira
A
Shimatsu