ACTA ENDOCRINOLOGICA (BUC)

Background. Fine needle aspiration biopsy (FNAB) is an important tool in the diagnosis of thyroid nodules. Aim. Our aim was to investigate the malignancy criteria in thyroid nodules by gray-scale ultrasonography (US) and duplex Doppler ultrasonography (DDUS), and their usefulness in reducing the number of unnecessary FNAB’s. Study design. This was a prospective observational study. Subjects and methods. 181 benign and 18 malignant thyroid nodules were evaluated by US and DDUS before FNAB or thyroidectomy. US was used to note size, shape, internal structure, nodule echogenicity, marginal properties, peripheral hypoechogenic halo, and microcalcifications. DDUS studies were used to evaluate the maximum and minimum flow velocity (Vmax and Vmin), systolic/diastolic flow velocity ratio (S/D), pulsatility index (PI), resistive index (RI), acceleration time (AT) and acceleration value. Results. Contour irregularity, size and presence of microcalcifications (p<0.001, p=0.02 and p=0.002, respectively) and S/D, Vmin, PI, RI and AT were significantly different (p=0.004, p=0.007, p=0.032, p=0.003 and p=0.003, respectively) were significant for malignant nodules. Benign and malignant nodules with or without suspicious US findings had similar DDUS findings. Vmax, Vmin, PI, RI, and AT were significantly different in the presence of microcalcification (p=0.043, p=0.001, p=0.031, p=0.04, and p=0.019 respectively). AT was significantly different in the case of absence of microcalcification (p=0.019). Comparing the irregular margins, Vmin, PI and RI were significantly different (p=0.014, p=0.003, and p=0.014 respectively). Conclusion. Benign and malignant thyroid nodules can be differentiated using gray-scale US findings and DDUS based indices together to reduce the number of unnecessary FNAB’s.

Background. Small-cell lung carcinoma is a neuroendocrine tumor that exhibits aggressive behavior, rapid growth, early spread to distant sites and frequent association with paraneoplastic syndromes, the most frequent being the syndrome of inappropriate secretion of antidiuretic hormone (SIADH). Case report. We present the case of a 66 year-old woman who presented to the Emergency Department for a syncope preceded by vomiting. She had onemonth history of progressive confusion, disorientation, drowsiness, and generalized malaise. At presentation, the biochemical profile showed normal hemogram values, severe hyponatremia (seric sodium level 120 mg/dL), low plasma osmolality (<275 mOsm/ kg). The blood tests for kidney, thyroid and adrenal functions were in normal limits. There was no evidence of congestive heart failure or nephrotic syndrome. A diagnosis of SIADH was made. Because of a high suspicion for lung cancer, chest computed tomography (CT) was done, together with neck, abdominal and pelvic CT scan, all showing normal data, excepting necrotic lymph nodes in the lower right carotid space and right paratracheal. Right laterocervical lymph node biopsy was done. The histopathological and immunohistochemical result showed lymph node metastasis of a neuroendocrine small cell carcinoma, most probably with broncho-pulmonary origin. Conclusion. The case is interesting due to long term absence of any respiratory symptom, absence of identification of pulmonary tumor, despite repeated CT scans, the only clinical manifestations being related to SIADH. Also, it emphasizes the importance of early recognition of SIADH, which may be the only initial manifestation of a neuroendocrine small cell carcinoma.