Prevalence of parathyroid cysts by neck ultrasound scan in unselected patients.

BACKGROUND: Parathyroid cysts (PC) are a rare entity, representing only 0.5-1% of all parathyroid lesions and <1% of neck masses. Since its first description, in the second half of the 19th century, fewer than 300 cases have been reported. By reviewing the literature, it appears that the data available arose from surgical series, and the precise incidence of PC as detected by ultrasound (US) has not been described. The aim of this study was to review 5 yr of routine neck US, mainly performed for thyroid diseases, in order to estimate the prevalence of PC in a large series of patients. METHODS: We reviewed our database of neck US investigations performed from 2003 to 2007: all data regarding patient's clinical history, US images, and fine needle aspiration cytology were retrospectively collected. RESULTS: Among 6621 patients submitted to neck US investigation, a PC (mean diameter 36.4+/-14.2 mm; range 25-61 mm) was diagnosed in 5 cases. Serum PTH levels were high in all the patients (221+/-140.7 pg/ml; range 111-456 pg/ml), whereas serum calcium levels only in 3 subjects (10.8+/-1.4 mg/dl; range 9.2-12.9 mg/ml). CONCLUSION: This is the first study evaluating the prevalence of PC in a large series of unselected patients by US. Our results demonstrate a much lower incidence (0.075%) of incidentally detected PC than previously reported.

The role of imaging in Graves' disease: a cost-effectiveness analysis.

According to many guidelines, scintigraphy remains the first suggested diagnostic procedure in hyperthyroid patients in spite of the widespread availability of ultrasounds. The aim of this study was to evaluate the cost-effectiveness of sonography versus scintigraphy in the management of Graves's disease, and to assess ultrasound features suggesting cancer in detecting thyroid nodules. Among 1470 hyperthyroid patients evaluated in our department from 2002 to 2005, 426 (29%) had Graves' disease: echographic and scintigraphic features were not suggestive of GD in 20/426 (4.8%) and 11/426 (2.6%) patients, respectively (p=0.763), even if one of the two procedures was almost always diagnostic. Ultrasound identified 68/426 (16%) patients with a concomitant solid lesion, while scintigraphy detected only 9/426 (2.1%) "cold" nodules (p<0.001). Thyroid cancer was diagnosed in 30/68 (47.7%) patients. Malignancy presented at ultrasound investigation blurred margins (26.7% versus 15.8%), microcalcifications (33.3% versus 28.9%) and an anteroposterior and transverse diameter ratio>or=1 (73.3% versus 71.1%); more frequently than benign nodules, but this was not statistically significant. The total cost to obtain a diagnosis by ultrasound was euro14645.34 (euro13312.5 for echography+euro1332.84 for scintigraphy in the 29 patients "negative" at echographic evaluation for GD) versus euro19922.71 by scintigraphy (euro19578.96 for scan+euro343.75 for ultrasounds in the 11 patients "negative" at scintigraphy). Our data show no difference in terms of diagnosis between sonography and scintigraphy. Indeed, scintigraphy was less sensitive in detecting nodules (often of malignant nature) than ultrasound, and, moreover, with a consequent increase of the direct cost of nodule management when scintigraphy is the first line procedure. In conclusion, according to our results, we suggest that ultrasounds with color-Doppler evaluation should be performed as first step in all hyperthyroid patients, and that scintigraphic examination should be limited only to the uncommon cases, where physician's observation, laboratory assays and/or ultrasounds are not diagnostic.

Fine needle cytology of complex thyroid nodules.

OBJECTIVE: To evaluate whether a preliminary aspiration (ASP) of the cystic component and/or using spinal needles in complex thyroid nodules (CTN) could improve the adequacy of cytological sampling. METHODS: Between January 2004 and December 2006, 386 consecutive patients with CTN were enrolled in this prospective investigation. Ultrasound (US) fine needle aspiration cytology (FNAC) of the solid component of the nodule (one nodule per patient) was performed using two different 25 gauge needles, with (Yale Spinal, YS) or without (Neolus, NS) a stylet, in alternate sequence on consecutive patients. In addition, a subgroup of patients presenting larger cystic component (approximately 50%) was submitted to total aspiration of the cystic component (ASP+) or not submitted (ASP-) before US-FNAC, in alternate sequence within each needle type group. All the samplings were performed by a single endocrinologist. RESULTS: Adequate specimens were observed in 163 (84.5%) and 183 (94.8%) nodules investigated by NS and YS respectively. Sampling with the stylet needle was associated with an overall significant reduction of non-diagnostic specimens (15.5% vs 5.2% by NS and YS respectively, P < 0.001). The favourable result obtained with YS was independent from preliminary aspiration of the cystic component (ASP+: 14.8% vs 5.7% by NS and YS; ASP-: 16.2% vs 4.8%, not significant). A logistic regression analysis, taking into account nodule size and presence of intranodal vascularity at eco-colour evaluation of the solid component, confirmed that needle type was the only significant predictor of successful sampling (odds ratio 3.6 (95% confidence interval 1.7-7.6), P < 0.001). CONCLUSIONS: Our data show that adopting stylet needles to perform FNAC in CTN may significantly improve the percentage of adequate sampling. On the other hand, preliminary aspiration of CTN with large cystic component does not add any advantage.

Aggressiveness and outcome of papillary thyroid carcinoma (PTC) versus microcarcinoma (PMC): a mono-institutional experience.

BACKGROUND: Papillary thyroid carcinoma (PTC) represents 70%-75% of well-differentiated thyroid cancers. Although most reports have shown that papillary thyroid microcarcinomas (PMC) follow an indolent course, a few series have demonstrated that a significant number of them are associated with extrathyroidal extension and nodal or distant metastases. METHODS: Four hundred eighty-four patients with papillary thyroid cancer (102, PMC; 382, PTC) were enrolled in this study. The median follow-up was 102 months. RESULTS: No difference between PTC and PMC patients was observed for age, gender, multifocality, extrathyroidal extension, and lymph nodes metastasis. The prevalence of nodal involvement developing during the follow-up period was significantly higher in PMC than PTC (58.8% vs. 38.5%, P = 0.002). An unfavorable clinical course occurred in 96 subjects (21.8%). Logistic analysis showed that the strongest association with the worst prognosis was found for age and TNM stage III (P < 0.001). Analysis also confirmed that the presence of intranodular vascularity is a predictor of unfavorable outcome (P = 0.044). CONCLUSIONS: 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.

Is the anteroposterior and transverse diameter ratio of nonpalpable thyroid nodules a sonographic criteria for recommending fine-needle aspiration cytology?

BACKGROUND: As a consequence of the increasing application of ultrasound (US) technology, the detection of asymptomatic nonpalpable thyroid nodules has generally increased. The aim of our study was to assess if the anteroposterior and transverse diameter ratio of nonpalpable thyroid nodules (A/T) > or = 1 could be a sonographic criterion for recommending fine-needle aspiration cytology (FNAC). METHODS: From January 2002 to January 2004, 828 consecutive solid nonpalpable thyroid nodules were evaluated by ultrasonography, colour-Doppler and FNAC in our department. Cases were selected from 2217 patients, referred to our thyroid unit for US-guided FNAC from the greater Brescia area, an endemic zone for goitre. Entry criteria included the presence at US of a solid thyroid nodule that was nonpalpable at physical examination, euthyroid condition and no previous diagnosis of thyroid malignancy. All patients with suspicious or malignant cytology underwent surgery. RESULTS: One hundred and twenty-seven nodules with inadequate cytology were excluded from the study. Thyroid malignancy was observed in 67 (9.6%) nodules. At US, cancers presented a solid hypoechoic appearance in 79.1% of cases, blurred margins in 47.8%, microcalcification in 73.1%, intranodular vascular pattern in 56.7% and A/T > or = 1 in 83.6%. A hypoechoic appearance (OR 4.3), blurred margins (OR 2.6), microcalcification (OR 6.1), intranodular vascular pattern (OR 10.2) and A/T > or = 1 (OR 22.4) were independent risk factors of malignancy. CONCLUSIONS: 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.

Cost-effectiveness of fine-needle-aspiration cytology of thyroid nodules with intranodular vascular pattern using two different needle types.

OBJECTIVE: To compare the cytological findings of hypoechoic thyroid nodules with intranodular vascular pattern (pattern II) obtained by two different needles (Neolus 25 gauge, Chemil, Wenzhou, China vs Yale Spinal 25 gauge, Becton Dickinson, Madrid, Spain) in euthyroid patients and to evaluate their cost-effectiveness. METHODS: From January 2001 to December 2003, 480 euthyroid patients with a hypoechoic thyroid nodule pattern II were referred for US-FNAC. The nodules were alternatively evaluated by Neolus or by Yale Spinal with the stylet (YS+) or without the stylet (YS-), in order to evaluate if the cytological results could be due to the presence of the stylet or to the different length of the two needles. For each nodule two passes were performed and the material was obtained by capillary action. Material was smeared on slides, fixed, and stained by Papanicolaou techniques. Cytological specimens were evaluated in blind by the same experienced cytopathologist. RESULTS: Inadequate cytological specimens because of blood contamination were present in 30 (18.7%) samples by Neolus needle and in 22 (13.8%) by YS- compared to only 5 (3.1%) by YS+. In 6 (20%) cases of the 30 repeated US-FNAC by Neolus and in 4 (18%) of the 22 US-FNAC by YS-, material remained inadequate for diagnosis because of blood contamination. All the five repeated samples obtained by YS+ became adequate for diagnosis and resulted benign nodules. Direct costs of US-FNAC procedure are currently 72.30 Euro including cytological examination. The cost of Neolus and Yale needles is 0.19 Euro and 3.0 Euro, respectively. The estimated total cost to obtain a cytological diagnosis by a Neolus needle (160 + 30 repeated US-FNAC) was 13809.2 Euro vs 12919.5 Euro by Yale Spinal needle (160 + 5 repeated US-FNAC). CONCLUSION: This study demonstrates that the use of Yale Spinal needles greatly reduces inadequate cytological specimens, and therefore limits both direct and indirect costs.