Maria Letizia Lai

Thyroid diseases cause mismatch between MIBI scan and neck ultrasound in the diagnosis of hyperfunctioning parathyroids: usefulness of FNA–PTH assay

DESIGN To evaluate the efficacy of the main tools in the diagnostic localization of hyperfunctioning parathyroids (HP) in primary hyperparathyroidism (pHPT) with concomitant thyroid diseases. METHODS Forty-three patients with pHPT associated with nodular goiter (NG, n=32) and/or autoimmune thyroid diseases (AITDs, n=11) for a total of 63 neck lesions were considered. Sixteen patients displaying HP (16 lesions), unequivocally localized by sestaMIBI scintigraphy (MIBI) and neck ultrasound (US) (group I), were compared with 27 patients (47 neck lesions) displaying equivocal parathyroid localization (group II). In all cases, neck US, MIBI scan, cytology, and parathyroid hormone assay in fine-needle aspiration washout fluid (FNA-PTH) were performed. All patients finally underwent surgery. RESULTS According to histological examination, high FNA-PTH values (>103 pg/ml) correctly identified all HP in both groups of patients (100% of sensitivity and specificity). Both MIBI and US correctly identified all HP only in group I patients; in contrast, four patterns of mismatch between these techniques were observed in group II patients, leading to low diagnostic performances of neck US (71.4% sensitivity and 78.9% specificity) and of MIBI scan (35.7% sensitivity and 42.1% specificity). The latter was due to both false-negative (mainly in AITD) and false-positive (mainly in NG) scan images. CONCLUSIONS Coexistent thyroid diseases are responsible for mismatch between MIBI and US images resulting in equivocal HP localization. In these cases, FNA-PTH resulted in the most accurate tool to identify HP. However, although safe, it should be advised only to patients with uncertain HP localization.

Association between carotid plaque enhancement shown by multidetector CT angiography and histologically validated microvessel density

PurposeCarotid plaques analysed by MDCTA can show contrast enhancement. The purpose of this study was to explore the association between carotid plaque enhancement (CPE) and microvessel density.Materials and methodsWe obtained IRB approval. Twenty-nine consecutive (male, 20; median age, 63) symptomatic patients studied with 16-detector CT were prospectively analysed. Examinations were performed before and after intravenous contrast medium administration, and analysis of plaque enhancement was performed. Patients underwent “en bloc” carotid endarterectomy; histological sections were prepared and the presence of microvessels quantified. Logistic regression analysis as well as ROC curve and area under the curve was calculated.ResultsA statistically significant association between the degree of CPE and microvessel density (P = 0.009; rho = 0.553) was observed. The ROC curve analysis confirmed this association with an area under the curve of 0.906, 0.735, 0.644 and 0.546 for CPE of 10 HU, 15 HU, 20 HU and 25 HU respectively. There was a statistically significant difference between the CPE and the degree of neovascularisation (P = 0.0003).ConclusionResults of this preliminary study suggest that CPE might be associated with the microvessel density. Histological analysis seems to demonstrate that the degree of intra-plaque neo-vascularisation is statistically associated with CPE.Key PointsCarotid artery plaque enhancement at CT is associated with microvessel density.The degree of intra-plaque neo-vascularisation is statistically associated with carotid plaque enhancement.Plaque enhancement at CT should be considered when assessing vulnerable plaques.

Renal cell carcinoma metastasis to thyroid tumor: a case report and review of the literature

IntroductionMetastatic neoplasms to the thyroid gland are rare in clinical practice. Clear cell renal carcinoma is the most frequent site of origin of thyroid metastases and represents 12 to 34% of all secondary thyroid tumors. Tumor-to-tumor metastases, in which a thyroid neoplasm is the recipient of a metastasis, are exceedingly rare. We report a case of clear cell renal carcinoma metastatic to a follicular adenoma. This is the tenth case of renal cell carcinoma metastasis to thyroid tumor reported in the literature.Case presentationA 62-year-old Caucasian woman with a history of clear cell renal carcinoma was admitted to our institution for multinodular goiter. A histological examination after total thyroidectomy revealed clear cell renal carcinoma metastasis to a thyroid follicular adenoma.ConclusionsPreoperative diagnosis of secondary thyroid neoplasm is difficult to achieve. The diagnosis of metastatic disease should be taken into account if patients have a history of clear cell renal carcinoma or if there is a multifocal growth pattern and clear cell appearance of the cytoplasm.

Assessing RET/PTC in thyroid nodule fine needle aspirates: the FISH point of view

RET/PTC rearrangement and BRAF(V600E) mutation are the two prevalent molecular alterations associated with papillary thyroid carcinoma (PTC), and their identification is increasingly being used as an adjunct to cytology in diagnosing PTC. However, there are caveats associated with the use of the molecular approach in fine-needle aspiration (FNA), particularly for RET/PTC, that should be taken into consideration. It has been claimed that a clonal or sporadic presence of this abnormality in follicular cells can distinguish between malignant and benign nodules. Nevertheless, the most commonly used PCR-based techniques lack the capacity to quantify the number of abnormal cells. Because fluorescence in situ hybridization (FISH) is the most sensitive method for detecting gene rearrangement in a single cell, we compared results from FISH and conventional RT-PCR obtained in FNA of a large cohort of consecutive patients with suspicious nodules and investigated the feasibility of setting a FISH-FNA threshold capable of distinguishing non-clonal from clonal molecular events. For this purpose, a home brew break-apart probe, able to recognize the physical breakage of RET, was designed. While a ≥3% FISH signal for broken RET was sufficient to distinguish nodules with abnormal follicular cells, only samples with a ≥6.8% break-apart FISH signal also exhibited positive RT-PCR results. On histological analysis, all nodules meeting the ≥6.8% threshold proved to be malignant. These data corroborate the power of FISH when compared with RT-PCR in quantifying the presence of RET/PTC in FNA and validate the RT-PCR efficiency in detecting clonal RET/PTC alterations.

Tall cell carcinoma arising in a thyroglossal duct cyst: A case report.

Introduction Thyroglossal duct cyst carcinomas are extremely rare and their clinical presentation is similar to that of benign cysts. The diagnosis is based on physical examination, laboratory tests, and most importantly multiple imaging techniques (ultrasonography, computed tomography and magnetic resonance imaging), and fine needle aspiration cytology. Presentation of case We report a very unusual case of a tall cell variant of papillary carcinoma arising in a thyroglossal duct cyst in association with a follicular variant of papillary microcarcinoma and a tall cell variant of papillary carcinoma arising from the thyroid gland. Discussion Although rarely described in the medical literature, ectopic thyroid tissue present in the thyroglossal duct cyst could be involved in the development of a poorly differentiated carcinoma. The frequent observation of an associated primitive thyroid carcinoma makes surgical management of thyroid gland controversial. Conclusion For the optimal management of this rare pathological condition, a comprehensive preoperative evaluation and meticulous intra-operative appraisal are fundamental.

Documentazione ecografica della comparsa di un carcinoma papillare della tiroide variante sclerosante diffusa in una giovane paziente con preesistente tiroidite autoimmune

La variante sclerosante diffusa del carcinoma papillare della tiroide (PTC-DSV), è una rara e aggressiva forma di PTC che insorge preferenzialmente nelle giovani donne [1]. Riportiamo le immagini ecografiche tiroidee di una sedicenne alla quale nell’ottobre del 2012 fu diagnosticata una tiroidite di Hashimoto con ipotiroidismo lieve sulla base di AbTPO positivi, TSH elevato (6,2 mcU/ml) e tipico quadro ecografico tiroideo “a nido d’ape” (Fig. 1a, c). La paziente iniziava terapia con L-T4 e controlli ecografici ogni 24 mesi. All’ecografia dell’aprile 2016 (Fig. 1b, d), si evidenziava nel terzo medio del lobo destro la comparsa ex novo di rari spot iperecogeni parenchimali in assenza di lesioni nodulari definite. Data la natura incerta dell’immagine, l’ecografia è stata ripetuta a breve termine nell’ottobre 2016 (Fig. 1e). In quell’occasione, il lobo tiroideo destro si mostrava diffusamente aumentato di volume ed ecostrutturalmente disomogeneo: ipoecogeno con accentuazione della trama connettivale, tempestato di spot iperecogeni. In sede laterocervicale omolaterale si identificava un linfonodo chiaramente ripetitivo. L’esame citologico su agoaspirato tiroideo ecoguidato del lobo destro deponeva per un PTC-DSV in tireopatia autoimmune. La paziente veniva sot-

Correspondence between Ultrasonography and Histological Features in a Single Thyroid Nodule with Coexisting Follicular Adenoma and Papillary Carcinoma

A 28-year-old woman was sent for ultrasound (US) evaluation of a right ‘‘cold’’ thyroid nodule, first detected 2 years ago. At that time, fine-needle aspiration cytology (FNAC), performed in a different institution without US guide, was consistent with a benign lesion, and follow-up without any therapy was advised. Physical examination showed a nontender 2.5 cm nodule in the lower third of the right thyroid lobe of increased consistency and not adherent to the underneath tissues. Serum thyroid-stimulating hormone, free thyroxine, and calcitonin concentrations were normal, and antithyroglobulin and antithyroid peroxidase autoantibodies were undetectable. US displayed a 26 mm solid nodule, in which two remarkably different areas were distinguishable (Fig. 1): an inner isoechoic portion was surrounded by a peripheral crescent-like hypoechoic zone, devoid of halo and with irregular borders. The approximate limit between the central normoechoic tissue and the peripheral hypoechoic portion is shown in Figure 1 by the dotted line. No microcalcifications were detected, and Colour Doppler displayed a faint intranodular vascularization without differences between hypoechoic and normoechoic areas. US-guided FNAC performed in the hypoechoic tissue was consistent with a follicular neoplasm with focal markedly atypical cells. On the basis of these results, surgery was recommended and a total thyroidectomy was performed. Histological examination showed that the nodule consisted of an encapsulated neoplasm composed of two regions with different architectural and nuclear features. These corresponded perfectly to the two areas identified on US. The white square depicted in Figure 2A displays the region corresponding to the low-magnification histological picture of the nodule (Fig. 2B). Figure 2B shows two different thyroid neoplasms: a follicular variant of papillary carcinoma on the left (corresponding to the hypoechoic area) and a well-differentiated follicular adenoma on the right (corresponding to the normoechoic area). The characteristics of the two neoplasms are clearly evident in higher magnification images (Fig. 2C, D). While it is well recognized that US is fundamental to guide the needle to position it correctly within the solid portion of partially cystic thyroid nodules, this case shows that US pattern might also be important to guide FNAC in some solid lesions that harbor both malignant and benign neoplasms.