Comparison of Ultrasonography and 99mTc-sestamibi Scan for Preoperative Localization of Parathyroid Adenoma / 대한내과학회지

BACKGROUND/AIMS: Primary hyperparathyroidism can be cured by minimally invasive surgery (MIS) with optimized preoperative localization. Ultrasonography (US) and 99mTc-sestamibi (MIBI) scan are the imaging modalities most widely used for the localization of the affected glands. In this study, we defined the roles of US and MIBI scan. METHODS: We retrospectively reviewed 40 patients who underwent parathyroidectomy for a single parathyroid adenoma between 2004 and 2013. US and scintigraphic findings were compared with operative findings. RESULTS: Adenomas were accurately localized using US and MIBI scan in 38 patients (95%) and 37 patients (92.5%), respectively. Twenty-nine patients (76.3%) showed typical extrathyroidal hypoechoic nodule with central or peripheral vascularity, and, after MIS, we confirmed that they were suffering from a single parathyroid adenoma. Eight patients with atypical US findings and two patients with an undetectable lesion on US underwent MIS after localization using MIBI scan or computed tomography (CT). Only one patient showed an extrathyroidal cystic nodule evidenced by high parathyroid hormone cystic fluid on ultrasound-guided fine-needle aspiration and negative MIBI scan. All lesions not localized on US were located in the superior portion. CONCLUSIONS: US is a sensitive and accurate method for the preoperative localization of parathyroid adenoma, especially if the lesion has typical US features and is located inferiorly. We suggest that US be the first localization modality and that MIBI scan or CT be used in the limited number of cases with negative US findings.

Hypoparathyroidism and Subclinical Hypothyroidism with Secondary Hemochromatosis

Hemochromatosis is an inherited genetic disorder of iron metabolism which can also occur as a secondary result of iron-overload. It leads to organ damage such as cardiomyopathy, liver cirrhosis, hypogonadism, and diabetes. This paper discusses a case of secondary hemochromatosis associated with repeated transfusions, presenting as asymptomatic hypoparathyroidism and subclinical hypothyroidism with multiple organ involvement. The 29-year-old female, who had severe aplastic anemia, received multiple transfusions totaling approximately 1,400 units of red blood cells over 15 years. During her routine laboratory examination, hypocalcemia was detected with decreased intact parathyroid hormone and increased thyroid stimulating hormone. Serum ferritin, iron, and total iron binding capacity had increased to 27,583.03 ng/mL, 291 microg/dL, and 389 microg/dL, respectively. She had unusually bronze skin and computed tomography revealed iron deposition in the thyroid, liver, and heart. Multiorgan involvement as seen in this case is rare in hemochromatosis associated with secondary transfusions. To the best of the author's knowledge, this is the first case report in Korea of hypoparathyroidism and subclinical hypothyroidism due to iron deposition in the parathyroid and thyroid gland.

Benign Teratoma of the Thyroid Gland

Although pathology reports of thyroid tissue in ovarian teratomas are abundant, benign teratomas of the thyroid are extremely rare in adolescents and adults. Therefore, their clinical characteristics are still not well characterized. We report a case of a 54-year-old woman with a growing mass in her neck. Left lobectomy of the thyroid revealed it to be a benign thyroid teratoma composed of tissues from all three germ layers. Preoperative evaluations included thyroid ultrasonography (US), ultrasound-guided fine needle aspiration cytology (FNAC), and computed tomography (CT) of the neck. A 4.7-cm, well defined, predominantly hypoechoic mass intermingled with hyperechoic internal lesions, was observed in the inferior portion of the left thyroid lobe with substernal extension on US. The posterior extent of the nodule was not visualized due to deep attenuation of the echo. US-guided FNAC failed to reveal any thyroid follicular cells, but suggested a benign cystic tumor. Neck CT hinted at the diagnosis of teratoma because the mass contained large amounts of fat, and the margin was well defined. Extrathyroidal extension and cervical lymphadenopathy were not seen. She underwent left thyroid lobectomy, and histologic examination confirmed benign thyroid teratoma. To the best of our knowledge, this is the first case report of benign thyroid teratoma in Korea.

The Effect of Ethanol Ablation for the Treatment of Benign Cystic Thyroid Nodules / 대한내과학회지

BACKGROUND/AIMS: The aims of this study were to evaluate the efficacy and safety of ultrasound-guided percutaneous ethanol ablation for benign cystic thyroid nodules, and to identify the clinical factors associated with therapeutic outcome. METHODS: We examined 46 patients with benign cystic nodules. After removal of cystic fluid, 99% ethanol was injected under ultrasound guidance. Follow-up ultrasonography was then performed 2 weeks and 6-36 months after the therapy to evaluate the early and late response, respectively. An effective response (ER) was defined as volume reduction > 50% or the absence of any residual cystic lesion; partial response (PR) as a 25-50% volume reduction; and no response (NR) as volume reduction < 25% or a volume expansion. RESULTS: During the early response, ER, PR, and NR were 67.4, 30.4, and 2.2%, respectively. The initial mean cyst volume of 12.0 +/- 7.8 mL (3.4-41.3) was reduced significantly after ethanol ablation therapy to 5.4 +/- 3.2 mL (0-33.0; 55% volume reduction, p < 0.001), and to a final late response volume of 4.4 +/- 3.4 mL (0-23.3; 63% volume reduction, p < 0.01). Except for 6 patients who received additional ethanol injection therapies, ER was obtained in 31 of 40 (77.5%) patients in the late response. A large initial volume was the factor associated with therapeutic failure (p = 0.04). Eleven patients (23%) reported transient mild local pain. CONCLUSIONS: Ultrasound-guided ethanol ablation is a safe and highly effective therapeutic method for cystic thyroid nodules. However, more sophisticated approaches are needed for large cystic nodules.