Risk of Malignancy in Thyroid Incidentalomas Identified by Fluorodeoxyglucose-Positron Emission Tomography

BACKGROUND: Thyroid incidentalomas detected by 2-deoxy-2-18F-fluoro-D-glucose positron emission tomography/computed tomography (18F-FDG PET/CT) have been reported in 1% to 4% of the population, with a risk of malignancy of 27.8% to 74%. We performed a retrospective review of FDG-avid thyroid incidentalomas in cancer screening subjects and patients with nonthyroid cancer. The risk of malignancy in thyroid incidentaloma and its association with the maximal standardized uptake value (SUVmax) in 18F-FDG PET/CT were evaluated to define the predictor variables in assessing risk of malignancy. METHODS: A total of 2,584 subjects underwent 18F-FDG PET/CT for metastatic evaluation or cancer screening from January 2005 to January 2010. Among them, 36 subjects with FDG-avid thyroid incidentalomas underwent further diagnostic evaluation (thyroid ultrasonography-guided fine needle aspiration cytology [FNAC] or surgical resection). We retrospectively reviewed the database of these subjects. RESULTS: Of the 2,584 subjects who underwent 18F-FDG PET/CT (319 for cancer screening and 2,265 for metastatic evaluation), 52 (2.0%) were identified as having FDG-avid thyroid incidentaloma and cytologic diagnosis was obtained by FNAC in 36 subjects. Of the subjects, 15 were proven to have malignant disease: 13 by FNAC and two by surgical resection. The positive predictive value of malignancy in FDG-avid thyroid incidentaloma was 41.7%. Median SUVmax was higher in malignancy than in benign lesions (4.7 [interquartile range (IQR), 3.4 to 6.0] vs. 2.8 [IQR, 2.6 to 4.0], P=0.001). CONCLUSION: Thyroid incidentalomas found on 18F-FDG PET/CT have a high risk of malignancy, with a positive predictive value of 41.7%. FDG-avid thyroid incidentalomas with higher SUVmax tended to be malignant.

A Case of the Drug Reaction with Eosinophilia and Systemic Symptom (DRESS) Following Isoniazid Treatment / 결핵및호흡기질환

The drug reaction with eosinophilia and systemic symptom (DRESS) syndrome is a severe adverse drug-induced reaction which includes a severe skin eruption, fever, hematologic abnormalities (eosinophilia or atypical lymphocytes) and internal organ involvement. The most frequently reported drug was anticonvulsants. The diagnosis of DRESS syndrome is challenging because the pattern of cutaneous eruption and the types of organs involved are various. The treatments for DRESS syndrome are culprit drug withdrawal and corticosteroids. Here we report a 71-year-old man with skin eruption with eosinophilia and hepatic and renal involvement that appeared 4 weeks after he had taken anti-tuberculosis drugs (isoniazid, ethambutol, rifampicin, and pyrazinamide), and resolved after stopping anti-tuberculosis drugs and the administration of systemic corticosteroids. DRESS recurred after re-challenging isoniazid, we identified isoniazid was causative drug.

A Case of Primary Empty Sella Syndrome with Central Diabetes Insipidus

Primary empty sella syndrome is a phenomenon caused by cerebrospinal fluid filling resulting from the herniation of the subarachnoid space within the sella. The pituitary function of primary empty sella syndrome is usually normal. But sometimes this syndrome causes some degree of pituitary dysfunction associated with hypersecretion or deficiency of pituitary hormone. Central diabetes insipidus with primary empty sella syndrome is rarely reported. Furthermore, most of those cases are accompanied by other pituitary dysfunction. We report here on a 35-year-old female who suffered from polyuria, polydipsia since childhood. She was diagnosed with central diabetes insipidus with primary empty sella syndrome. She had no anterior pituitary dysfunction except mild hyperprolactinemia.