Nadia Sorgato

Coronary Microvascular Dysfunction Induced by Primary Hyperparathyroidism is Restored After Parathyroidectomy

Background— Symptomatic primary hyperparathyroidism (PHPT) is associated with increased cardiovascular mortality. However, data on the association between asymptomatic PHPT and cardiovascular risk are lacking. We assessed coronary flow reserve (CFR) as a marker of coronary microvascular function in asymptomatic PHPT of recent onset. Methods and Results— We studied 100 PHPT patients (80 women; age, 58±12 years) without cardiovascular disease and 50 control subjects matched for age and sex. CFR in the left anterior descending coronary artery was detected by transthoracic Doppler echocardiography, at rest, and during adenosine infusion. CFR was the ratio of hyperemic to resting diastolic flow velocity. CFR was lower in PHPT patients than in control subjects (3.0±0.8 versus 3.8±0.7; P<0.0001) and was abnormal (⩽2.5) in 27 patients (27%) compared with control subjects (4%; P=0.0008). CFR was inversely related to parathyroid hormone (PTH) levels (r=−0.3, P<0.004). In patients with CFR ⩽2.5, PTH was higher (26.4 pmol/L [quartiles 1 and 3, 16 and 37 pmol/L] versus 18 [13–25] pmol/L; P<0.007), whereas calcium levels were similar (2.9±0.1 versus 2.8±0.3 mmol/L; P=0.2). In multivariable linear regression analysis, PTH, age, and heart rate were the only factors associated with CFR (P=0.04, P=0.01, and P=0.006, respectively). In multiple logistic regression analysis, only PTH increased the probability of CFR ⩽2.5 (P=0.03). In all PHPT patients with CFR ⩽2.5, parathyroidectomy normalized CFR (3.3±0.7 versus 2.1±0.5; P<0.0001). Conclusions— PHPT patients have coronary microvascular dysfunction that is completely restored after parathyroidectomy. PTH independently correlates with the coronary microvascular impairment, suggesting a crucial role of the hormone in explaining the increased cardiovascular risk in PHPT.

BRAF analysis by fine needle aspiration biopsy of thyroid nodules improves preoperative identification of papillary thyroid carcinoma and represents a prognostic factor. A mono-institutional experience.

Abstract Background: The current preoperative diagnosis of a thyroid mass relies on microscopic evaluation of thyroid cells obtained by fine needle aspiration biopsy (FNAB). More recently, FNAB has been combined with molecular analysis to increase the accuracy of the cytological evaluation. In this mono-institutional prospective study, we evaluated whether the routine introduction of BRAF testing in thyroid FNAB could help ameliorate the preoperative recognition of papillary thyroid carcinoma (PTC) in “suspended” or malignant cytological categories. Moreover, we investigated the prognostic role of the BRAFV600E mutation in PTC. Methods: BRAFV600E analysis was performed in thyroid FNAB from 270 patients classified into one of five cytological categories THY1, THY2, THY3, THY4, THY5. All subsequently underwent thyroidectomy±node dissection, from October 2008 to September 2009 in our Department. For each cytological category, we considered the definitive histological diagnosis of PTC and the presence of the BRAFV600E mutation. In 141 patients with a final tissue diagnosis of PTC, we correlated the presence of BRAFV600E with gender, age, histotype, TNM, size of the lesion, extracapsular extension, node metastases and multifocality. Results: The prevalence of the BRAFV600E mutation, among PTCs at final tissue diagnosis, was 69%. It improved the FNAB diagnostic accuracy from 88% to 91%. The BRAFV600E mutation was correlated with older age, classical variant of PTC, advanced stages in patients >45 years. Conclusions: BRAFV600E testing could play a role in improving the diagnostic accuracy of FNAB for PTC, representing a useful adjuvant tool in presurgical characterization of thyroid nodes in particular cases. There is an association between the BRAFV600E mutation and some clinico-pathological characteristics of PTC.

FDG-PET/CT and parathyroid carcinoma: Review of literature and illustrative case series

Parathyroid cancer is an uncommon malignant cancer and is associated with a poor prognosis. The staging of parathyroid cancer represents an important issue both at initial diagnosis and after surgery and medical treatment. The role of positron emission tomography/computed tomography (PET/CT) with 18F-Fluorodeoxyglucose (18F-FDG) as an imaging tool in parathyroid cancer is not clearly reported in the literature, although its impact in other cancers is well-defined. The aim of the following illustrative clinical cases is to highlight the impact of PET/CT in the management of different phases of parathyroid cancer. We describe five patients with parathyroid malignant lesions, who underwent FDG PET/CT at initial staging, restaging and post-surgery evaluation. In each patient we report the value of PET/CT comparing its findings with other common imaging modalities (e.g., CT, planar scintigraphy with 99mTc-sestamibi, magnetic resonance imaging) thus determining the complementary benefit of FDG PET/CT in parathyroid carcinoma. We hope to provide an insight into the potential role of PET/CT in assessing the extent of disease and response to treatment which are the general principles used to correctly evaluate disease status.

Rapid intraoperative parathyroid hormone assay in fine needle aspiration for differential diagnosis in thyroid and parathyroid surgery

Abstract Background: The purpose of our study was to investigate the efficacy of rapid intraoperative parathyroid hormone (rIO-PTH) analysis performed using material collected by fine needle aspiration as a parameter to distinguish anatomical structures which the surgeon is not able to identify clearly as parathyroid or lymph node during thyroid/parathyroid surgery. Before surgery, all patients gave written, informed consent. Methods: We measured the rIO-PTH on 50 anatomical structures, 32 presumed parathyroids and 18 presumed lymph nodes from 22 patients, who underwent thyroid/parathyroid surgery between May and September 2009. Results: The rIO-PTH values obtained on parathyroids ranged from 85.4 pmol/L to more than 2106 pmol/L, with a rIO-PTH median of 263.25 pmol/L. Results obtained on lymph nodes ranged from <0.52 pmol/L up to 20.4 pmol/L, with a rIO-PTH median equal to 1.31 pmol/L. Results of the Mann-Whitney test showed a rIO-PTH median significantly different (p<0.0001) between samples obtained from parathyroid glands and lymph node tissue. Conclusions: We demonstrated that rapid intraoperative measurement of parathyroid hormone is a good parameter for the differential diagnosis of parathyroid vs. lymph node tissue. We suggest extending the use of this technique to the field of parathyroid preservation during thyroid/parathyroid surgery in those cases where the parathyroids prove difficult to recognize on the basis of topographic or morphologic criteria. Clin Chem Lab Med 2010;48:1313–7.

Does the ultrasound dissector improve parathyroid gland preservation during surgery

BACKGROUND The most common complication of thyroid surgery is hypoparathyroidism, usually temporary. Ischemic injury or parathyroid avulsion are the causes of surgical hypoparathyroidism. We assessed the value of an ultrasound scalpel, the Harmonic Focus(®) (HF), could prevent surgical-related hypoparathyroidism. METHODS Patients consecutively undergoing total thyroidectomy using the HF from November 2009 to February 2011 were recruited and their clinical characteristics, type of operation, histology, and postoperative calcium levels (normal range: 2.10-2.55 mMol/l) were recorded. The prevalence of transient and permanent hypocalcemia was calculated for benign vs. malignant diseases and compared with a control group of 147 patients treated surgically in 2005 using manual technique. RESULTS 139 patients treated by the same surgeon with a total thyroidectomy (41.7% for a malignant disease) were considered. Prevalence of transient hypoparathyroidism (THP) was 45.2% and of definitive hypoparathyroidism (DHP) 1.4%. None of the patients with malignancies were hypocalcemic at 1-year follow-up. In the control group THP was found in 51.7% of cases and DHP in 5.4% (p < 0.001). CONCLUSIONS Use of the ultrasound scalpel improved the likelihood of the parathyroid glands preservation during thyroid surgery. Paradoxically, the HF appears to be more effective in treating malignant disease, i.e. when central node dissection is required.