No single parameter, including nodule size, satisfactorily identifies a subset of patients to be electively investigated by FNAC, although several may be useful in this regard.

Objective: To evaluate if a nodule with shape taller than wide (anteroposterior/transverse diameter ratio, A/TR1) is a good predictor of malignancy independent of the size. Methods: We retrospectively examined the cytological and histological results of 7455 nodules (5198 patients) referred for ultrasound-guided-fine needle aspiration cytology (US-FNAC) in our hospital from January 1991 to September 2004. Results: A suitable FNAC was obtained from 6135 nodules (4495 patients); 34.6% were less than 1 cm in diameter (small nodules, SN). A diagnosis of carcinoma was histologically confirmed in 284/349 suspicious lesions after FNAC. The size of carcinoma nodules was not significantly associated with the occurrence of extracapsular growth (large nodules (LN): 10.5%, SN: 4.9%, NS) and lymph node metastasis (LN: 23.6%, SN: 25.0%, NS). Malignant lesions showed microcalcifications more frequently than benign nodules (72.2 vs 28.7%; P!0.001; (odds ratio, OR(confidence intervals, CI)Z9.9(7.2-13.4)). Similarly, A/TR1 (76 vs 40%; P!0.001; OR(CI)Z8.6(5.5-13.1)), blurred margins (52.8 vs 18.8%; P!0.001; OR(CI)Z7.7(5.6-10.2)), solid hypo-echoic appearance (80.6 vs 52.4%; P!0.001; OR(CI)Z 3.2(2.2-4.3)) and intranodular vascular pattern (type 2) (61.6 vs 49.7%; P!0.001; OR(CI)Z 1.7(1.3-2.3)) were significantly more frequent in malignant than in benign nodules. Conclusions: Our data show that no single parameter, including nodule size, satisfactorily identifies a subset of patients to be electively investigated by FNAC. We concluded that A/TR1 with at least two of US features (microcalcification, blurred margins, hypo-echoic pattern) is today the best compromise between missing cancers and cost-benefit.

OBJECTIVETo assess the interplay between metformin treatment and thyroid function in type 2 diabetic patients.RESEARCH DESIGN AND METHODSThe acute and long-term effects of metformin on thyroid axis hormones were assessed in diabetic patients with primary hypothyroidism who were either untreated or treated with levothyroxine (L-T4), as well as in diabetic patients with normal thyroid function.RESULTSNo acute changes were found in 11 patients with treated hypothyroidism. After 1 year of metformin administration, a significant thyrotropin (TSH) decrease (P < 0.001) was observed in diabetic subjects with hypothyroidism who were either treated (n = 29; from 2.37 ± 1.17 to 1.41 ± 1.21 mIU/l) or untreated (n = 18; 4.5 ± 0.37 vs. 2.93 ± 1.48) with L-T4, but not in 54 euthyroid subjects. No significant change in free T4 (FT4) was observed in any group.CONCLUSIONSMetformin administration influences TSH without change of FT4 in patients with type 2 diabetes and concomitant hypothyroidism. The need for reevaluation of thyroid function in these patients within 6–12 months after starting metformin is indicated.

We suggest always performing a total thyroidectomy followed by radiometabolic therapy in papillary carcinomas independent of their size. If the choice in PMCs should be more conservative (hemithyroidectomy), we purpose to limit this procedure to the cancers without Doppler features suggesting intranodular vascular pattern.

A/T > or = 1 in conjunction with at least one other sonographic risk factor is able to detect the majority of carcinoma and, moreover, it limits the FNAC procedures to only 15.9% of all the nodules.