BackgroundThe intraoperative parathyroid hormone (IOPTH) assay is widely used in patients with primary hyperparathyroidism (PHPT). We investigated the usefulness of the IOPTH assay in Korean patients with PHPT.MethodsWe retrospectively reviewed the data of 33 patients with PHPT who underwent parathyroidectomy. Neck ultrasonography (US) and 99mTc-sestamibi scintigraphy (MIBI scan) were performed preoperatively and IOPTH assays were conducted.ResultsThe sensitivity of neck US and MIBI scans were 91% and 94%, respectively. A 50% decrease in parathyroid hormone (PTH) levels 10 minutes after excision of the parathyroid gland was obtained in 91% (30/33) of patients and operative success was achieved in 97% (32/33) of patients. The IOPTH assay was 91% true-positive, 3% true-negative, 0% false-positive, and 6% false-negative. The overall accuracy of the IOPTH assay was 94%. In five cases with discordant neck US and MIBI scan results, a sufficient decrease in IOPTH levels helped the surgeon confirm the complete excision of the parathyroid gland with no additional neck exploration.ConclusionThe IOPTH assay is an accurate tool for localizing hyperfunctioning parathyroid glands and is helpful for evaluating cases with discordant neck US and MIBI scan results.

Nodular lymphoid hyperplasia (NLH) is a benign lymphoproliferative disease that can affect the lung. Because of its rarity, little is known about the etiology and natural history of NLH. Most cases are usually asymptomatic and found incidentally on imaging studies. Imaging finding of NLH has shown most commonly as a solitary lesion, although multifocal pulmonary nodules may be seen. Surgical resection has proved curative in the cases previously described. We report a rare case of NLH in a 55 year-old man who presented with bilateral multiple pulmonary nodules on chest radiography. Open biopsy was performed from the upper and lower lobe of the left lung. The lesions were pathologically diagnosed as pulmonary NLH. Multifocal residual nodules in both lungs remain stable without spontaneous regression during the 3 years of follow-up.

Hepatocellular carcinoma (HCC) is the fifth most common cancer in Korea. Diverse paraneoplastic syndromes can occur in patients with HCC, but parathyroid hormone-related peptide (PTH-rP)-induced hypercalcemia is uncommon. Hypercalcemia due to PTH or particularly PTH-rP-secreting HCC is associated with poor outcomes. We report a 71-year-old man who presented with symptoms of vague abdominal discomfort, somnolence, lethargy, nausea, vomiting, and weight loss. Imaging studies revealed a large HCC without metastasis. The laboratory findings showed elevated serum calcium level, low intact parathyroid hormone (iPTH) level and elevated PTH-rP level. These results led to a diagnosis of a PTH-rP-secreting HCC and paraneoplastic hypercalcemia. After emergency management of the hypercalcemia, the patient underwent an extended right hemihepatectomy with cholecystectomy. One year after the surgery, he is alive with normal calcium, PTH-rP, and iPTH levels. This case demonstrates that the rare phenomenon of life-threatening hypercalcemia caused by HCC should not be overlooked. These symptoms offer a good opportunity to diagnose HCC early. Radical tumor resection makes it possible to cure patients with PTH-rP-secreting HCC.