Tumor Grade and Molecular Characteristics Associated with Survival in Sporadic Medullary Thyroid Carcinoma

Background: The International Medullary Thyroid Carcinoma Grading System (IMTCGS) divides medullary thyroid carcinoma (MTC) into two categories, high- and low-grade tumors, which has a profound impact on patient outcomes. The aim of this study was to explore the association between IMTCGS grading, clinical data, and molecular status in sporadic MTC. Methods: A retrospective cohort study was performed on consecutive sporadic MTCs from patients undergoing initial surgery between January 2000 and January 2022 at the Padua Endocrine Surgery Unit. Clinical, pathological, and follow-up data were collected, tumors were graded, and somatic mutations of RET and RAS genes were analyzed. Patient outcomes were based on Ct levels and MTC-related deaths. Survival analyses were carried out employing the Kaplan-Meier method and the log-rank test. A Cox proportional hazard regression model was employed for multivariable survival analysis with the following covariates: somatic RET mutation, MTC stage at diagnosis, sex, age at diagnosis, and IMTCGS grade. Results: We included 141 consecutive sporadic MTCs. The median follow-up was 80.0 months (interquartile ranges: 41.5-122.5 months). Seventeen patients (12.1%) died from disease-related causes. 107/141 (76.9%) were classified as low-grade tumors, 32/141 (23.1%) as high-grade. Patients carrying a RET mutation had more aggressive features and shorter disease-specific survival (DSS) (p = 0.001) and were more frequently classified high-grade than low-grade MTC (p < 0.001). At multivariable survival analysis, only IMTCGS grading was independently associated with DSS (hazard ratio 8.8 [confidence interval: 2.7-28.3], p = 0.005). RET mutations, in particular RET-M918T, were more frequent in high-grade than in low-grade MTC (68.8% vs. 29.4% mutated in RET, 46.9% vs. 12.7% mutated in RET-M918T; p < 0.001). None of the high-grade tumors was mutated in the RAS gene, but the mutation was present in 11.8% of low-grade tumors. Conclusions: IMTCGS grading was associated with DSS independently of other clinical, pathological, and molecular factors. Moreover, MTC grading was associated with RET and RAS patterns, which explains, at least in part, the molecular basis of the aggressive behavior of high-grade MTC.

Sentinel lymph node mapping: current applications and future perspectives in thyroid carcinoma

Sentinel lymph node (SLN) mapping is a standard, minimally-invasive diagnostic method in the surgical treatment of many solid tumors, as for example melanoma and breast cancer, for detecting the presence of regional nodal metastases. A negative SLN accurately indicates the absence of metastases in the other regional lymph nodes (LN), thus avoiding unnecessary lymph nodal dissection. Papillary thyroid carcinoma (PTC) is the most common type of thyroid carcinoma (TC) with cervical LN metastases at diagnosis in 20-90%, and nodal involvement correlates with local persistence/recurrence. The SLN in PTC is an intraoperative method for staging preoperative N0 patients and for detecting metastatic LNs "in and outside" the cervical LN central compartment; it represents an alternative method to prophylactic central neck node dissection. In this review we summarize different methods and results of the use of SLN in TC. The SLN identification techniques currently used include the selective vital-dye (VD) method, 99mTc-nanocolloid planar lymphoscintigraphy with intraoperative use of a hand-held gamma probe (LS), the combination LS + VD, and the combination LS and preoperative SPECT-CT (LS + SPECT/CT). The application of the SLN procedure in TC has been described in many studies, however, the techniques are heterogeneous, and the role of SLN in TC, with indications, results, advantages and limits, is still debated.

Parathyroid Retrospective Analysis of Neoplasms Incidence (pTRANI Study): An Italian Multicenter Study on Parathyroid Carcinoma and Atypical Parathyroid Tumour

BACKGROUND

Parathyroid cancer (PC) is a rare sporadic or hereditary malignancy whose histologic features were redefined with the 2022 WHO classification. A total of 24 Italian institutions designed this multicenter study to specify PC incidence, describe its clinical, functional, and imaging characteristics and improve its differentiation from the atypical parathyroid tumour (APT).

METHODS

All relevant information was collected about PC and APT patients treated between 2009 and 2021.

RESULTS

Among 8361 parathyroidectomies, 351 patients (mean age 59.0 ± 14.5; F = 210, 59.8%) were divided into the APT (n = 226, 2.8%) and PC group (n = 125, 1.5%). PC showed significantly higher rates (p < 0.05) of bone involvement, abdominal, and neurological symptoms than APT (48.8% vs. 35.0%, 17.6% vs. 7.1%, 13.6% vs. 5.3%, respectively). Ultrasound (US) diameter >3 cm (30.9% vs. 19.3%, p = 0.049) was significantly more common in the PC. A significantly higher frequency of local recurrences was observed in the PC (8.0% vs. 2.7%, p = 0.022). Mortality due to consequences of cancer or uncontrolled hyperparathyroidism was 3.3%.

CONCLUSIONS

Symptomatic hyperparathyroidism, high PTH and albumin-corrected serum calcium values, and a US diameter >3 cm may be considered features differentiating PC from APT. 2022 WHO criteria did not impact the diagnosis.

Medullary thyroid carcinoma

INTRODUCTION

Medullary thyroid carcinoma (MTC) constitutes approximately 5-10% of all thyroid cancers. Although the tumor forms in the thyroid, it doesn't originate from thyroid cells, but from the C cells or parafollicular cells which produce and release a hormone called calcitonin (CT). Starting from the second half of the 1900s, MTC was progressively studied and defined.

AREAS COVERED

This study aims to analyze the history, clinical presentation and biological behavior of MTC, bio-humoral and instrumental diagnosis, molecular profiling, genetic screening, preoperative staging and instrumental procedures, indispensable in expert and dedicated hands, such as high-resolution ultrasonography, CT-scan, MRI and PET/TC. We examine recommended and controversial surgical indications and procedures, prophylactic early surgery and multiple endocrine neoplasia surgery. Also, we discuss pathological anatomy classification and targeted therapies. The role of serum CT is valued both as undisputed and constant preoperative diagnostic marker, obscuring cytology and as early postoperative marker that predicts disease persistence.

EXPERT OPINION

With a complete preoperative study, unnecessary or useless, late and extended interventions can be reduced in favor of tailored surgery that also considers quality of life. Finally, great progress has been made in targeted therapy, with favorable impact on survival.

Validation of miRNAs as diagnostic and prognostic biomarkers, and possible therapeutic targets in medullary thyroid cancers

Introduction

Medullary thyroid cancer (MTC) is a rare type of neuroendocrine tumor that produces a hormone called calcitonin (CT). Thyroidectomy is the preferred treatment for MTC, as chemotherapy has been shown to have limited effectiveness. Targeted therapy approaches are currently being used for patients with advanced, metastatic MTC. Several studies have identified microRNAs, including miR-21, as playing a role in the development of MTC. Programmed cell death 4 (PDCD4) is a tumor suppressor gene that is an important target of miR-21. Our previous research has shown that high levels of miR-21 are associated with low PDCD4 nuclear scores and high CT levels. The aim of this study was to investigate the potential of this pathway as a novel therapeutic target for MTC.

Methods

We used a specific process to silence miR-21 in two human MTC cell lines. We studied the effect of this anti-miRNA process alone and in combination with cabozantinib and vandetanib, two drugs used in targeted therapy for MTC. We analyzed the effect of miR-21 silencing on cell viability, PDCD4 and CT expression, phosphorylation pathways, cell migration, cell cycle, and apoptosis.

Results

Silencing miR-21 alone resulted in a reduction of cell viability and an increase in PDCD4 levels at both mRNA and protein levels. It also led to a reduction in CT expression at both mRNA and secretion levels. When combined with cabozantinib and vandetanib, miR-21 silencing did not affect cell cycle or migration but was able to enhance apoptosis.

Conclusion

Silencing miR-21, although not showing synergistic activity with TKIs (tyrosine kinase inhibitors), represents a potential alternative worth exploring as a therapeutic target for MTC.

Safety and efficacy of prophylactic treatment for hyperthyroidism induced by iodinated contrast media in a high-risk population

Introduction

The use of iodinated contrast media (ICM) can lead to thyrotoxicosis, especially in patients with risk factors, such as Graves' disease, multinodular goiter, older age, and iodine deficiency. Although hyperthyroidism may have clinically relevant effects, whether high-risk patients should receive prophylactic treatment before they are administered ICM is still debated.

Aim of the study

We aimed to demonstrate the safety and efficacy of prophylactic treatment with sodium perchlorate and/or methimazole to prevent ICM-induced hyperthyroidism (ICMIH) in a population of high-risk cardiac patients. We ran a cost analysis to ascertain the most cost-effective prophylactic treatment protocol. We also aimed to identify possible risk factors for the onset of ICMIH.

Materials and methods

We performed a longitudinal retrospective study on 61 patients admitted to a tertiary-level cardiology unit for diagnostic and/or therapeutic ICM-procedures. We included patients with available records of thyroid function tests performed before and after ICM were administered, who were at high risk of developing ICMIH. Patients were given one of two different prophylactic treatments (methimazole alone or both methimazole and sodium perchlorate) or no prophylactic treatment. The difference between their thyroid function at the baseline and 11-30 days after the ICM-related procedure was considered the principal endpoint.

Results

Twenty-three (38%) of the 61 patients were given a prophylactic treatment. Thyroid function deteriorated after the administration of ICM in 9/61 patients (15%). These cases were associated with higher plasma creatinine levels at admission, higher baseline TSH levels, lower baseline FT4 levels, and no use of prophylactic treatment. The type of prophylaxis provided did not influence any onset of ICMIH. A cost-benefit analysis showed that prophylactic treatment with methimazole alone was less costly per person than the combination protocol. On multivariate analysis, only the use of a prophylactic treatment was independently associated with a reduction in the risk of ICMIH. Patients not given any prophylactic treatment had a nearly five-fold higher relative risk of developing ICMIH.

Conclusion

Prophylactic treatment can prevent the onset of ICMIH in high-risk populations administered ICM. Prophylaxis is safe and effective in this setting, especially in cardiopathic patients. Prophylaxis with methimazole alone seems to be the most cost-effective option.

Papillary Thyroid Carcinoma: Molecular Distinction by MicroRNA Profiling

Papillary thyroid carcinoma (PTC) is a miscellaneous disease with a variety of histological variants, each with its own mutational profile, and clinical and prognostic characteristics. Identification of microRNA (miRNA) expression profiles represents an important benchmark for understanding the molecular mechanisms underlying the biological behavior of these unique PTC subtypes in order that they be better characterized. We considered a series of 35 PTC samples with a histological diagnosis of either hobnail (17 cases) or classical variant (nine cases) and with a specific BRAF p.K601E mutation (nine cases). We determined the overall miRNA expression profile with NanoString technology, and both quantitative reverse transcription-PCR and in situ hybridization were used to confirm selected miRNAs. The miRNA signature was found to consistently differentiate specific histotypes and mutational profiles. In contrast to the BRAF p.K601E mutation and classic PTCs, three miRNAs (miR-21-5p, miR-146b-5p, and miR-205-5p) were substantially overexpressed in the hobnail variant. The current study found that different miRNA signature profiles were linked to unique histological variants and BRAF mutations in PTC. Further studies focusing on the downstream pathogenetic functions of mRNAs in thyroid neoplasms are warranted.

Attenuation Value in Adrenal Incidentalomas: A Longitudinal Study

Context

A tendency to grow has been reported in adrenal incidentalomas. However, long-term data regarding attenuation value, a measure of lipid content, are not available.

Aim

This study aims to collect radiological data (diameter in mm and attenuation value in Hounsfield units, HU) with computed tomography (CT) in adrenal incidentalomas, in order to compare baseline characteristics with the last follow-up imaging.

Design

This is a longitudinal study which included patients with a new diagnosis of adrenal incidentaloma, evaluated from January 2002 to June 2020.

Setting

Referral University-Hospital center.

Patients

Two hundred seventy-seven patients with 355 different cortical adenomas (baseline group) were evaluated at the first outpatient visit; the follow-up cohort consists of 181 patients with 234 adenomas (12-175 months after baseline). Inclusion criteria were conservative management and radiological features able to minimize malignancy or risk of progression.

Main Outcome Measure

CT modification according to endocrine function: autonomous cortisol secretion (ACS) if cortisol >50 nmol/L after 1-mg dexamethasone test (DST).

Results

At baseline CT, mean diameter was 18.7 mm and attenuation value was 0.8 HU (higher in ACS, 66 cases >10 HU), without modification in early imaging (12-36 months). The size increased over time (r = 0.289), achieving the largest differences after at least 60 months of follow-up (mean diameter, +2 mm; attenuation value, -4 HU), combined with a reduction in the attenuation value (r = -0.195, especially in patients with ACS). Lipid-poor adenomas (>10 HU) presented a reduced cortisol suppression after 1-mg DST, an increase in size and the largest decrease in attenuation value during follow-up. Univariate analysis confirmed that larger adenomas presented reduced suppression after DST and increase in size during follow-up.

Conclusions

Growth is clinically modest in adrenal incidentaloma: the first follow-up CT 5 years after baseline is a reasonable choice, especially in ACS. Mean density is increased in patients with ACS and overt hypercortisolism. Mean density reduces during follow-up in all adrenal adenomas, suggesting an increase in lipid content, especially in those with ACS.

Clinical presentation and management of acromegaly in elderly patients

BACKGROUND AND AIM

Acromegaly is a rare disease with a peak of incidence in early adulthood. However, enhanced awareness of this disease, combined with wide availability of magnetic resonance imaging (MRI), has increased the diagnosis of forms with mild presentation, especially in elderly patients. Moreover, due to increased life expectancy and proactive individualized treatment, patients with early-onset acromegaly are today aging. The aim of our study was to describe our cohort of elderly patients with acromegaly.

MATERIALS AND METHODS

This is a cross-sectional retrospective study of 96 outpatients. Clinical, endocrine, treatment, and follow-up data were collected using the electronic database of the University Hospital of Padova, Italy.

RESULTS

We diagnosed acromegaly in 13 patients, aged ≥65 years, presenting with relatively small adenomas and low IGF-1 secretion. Among them, 11 patients were initially treated with medical therapy and half normalized hormonal levels after 6 months without undergoing neurosurgery (TNS). Remission was achieved after TNS in three out of four patients (primary TNS in two); ten patients presented controlled acromegaly at the last visit. Acromegaly-related comorbidities (colon polyps, thyroid cancer, adrenal incidentaloma, hypertension, and bone disease) were more prevalent in patients who had an early diagnosis (31 patients, characterized by a longer follow-up of 24 years) than in those diagnosed aged ≥65 years (5 years of follow-up).

CONCLUSIONS

Elderly acromegalic patients are not uncommon. Primary medical therapy is a reasonable option and is effectively used, while the rate of surgical success is not reduced. A careful cost-benefit balance is suggested. Disease-specific comorbidities are more prevalent in acromegalic patients with a longer follow-up rather than in those diagnosed aged ≥65 years.

Predictivity of clinical, laboratory and imaging findings in diagnostic definition of palpable thyroid nodules. A multicenter prospective study

PURPOSE

To assess the role of clinical, biochemical, and morphological parameters, as added to cytology, for improving pre-surgical diagnosis of palpable thyroid nodules.

METHODS

Patients with a palpable thyroid nodule were eligible if surgical intervention was indicated after a positive or suspicious for malignancy FNAC (TIR 4-5 according to the 2007 Italian SIAPEC-IAP classification), or two inconclusive FNAC at a ≥3 months interval, or a negative FNAC associated with one or more risk factor. Reference standard was histological malignancy diagnosis. Likelihood ratios of malignancy, sensitivity, specificity, negative (NPV), and positive predictive value (PPV) were described. Multiple correspondence analysis (MCA) and logistic regression were applied.

RESULTS

Cancer was found in 433/902 (48%) patients. Considering TIR4-5 only as positive cytology, specificity, and PPV were high (94 and 91%) but sensitivity and NPV were low (61 and 72%); conversely, including TIR3 among positive, sensitivity and NPV were higher (88 and 82%) while specificity and PPV decreased (52 and 63%). Ultrasonographic size ≥3 cm was independently associated with benignity among TIR2 cases (OR of malignancy 0.37, 95% CI 0.18-0.78). In TIR3 cases the hard consistency of small nodules was associated with malignity (OR: 3.51, 95% CI 1.84-6.70, p < 0.001), while size alone, irrespective of consistency, was not diagnostically informative. No other significant association was found in TIR2 and TIR3.

CONCLUSIONS

The combination of cytology with clinical and ultrasonographic parameters may improve diagnostic definition of palpable thyroid nodules. However, the need for innovative diagnostic tools is still high.

Specifying the molecular pattern of sporadic parathyroid tumorigenesis-The Y282D variant of the GCM2 gene

OBJECTIVE

Sporadic carcinoma of the parathyroid glands is a rare malignant neoplasia. The GCM2 gene encodes a transcription factor that is crucial to embryonic parathyroid development. The Y282D variant of GCM2 exhibits increased transcriptional activity, and the presence of this variant is significantly associated with a higher prevalence of primitive hyperparathyroidism. The present study investigated the prevalence of the Y282D variant of the GCM2 gene and its association with clinical parameters in patients with a definitive histological diagnosis of sporadic parathyroid carcinoma (SPC) or atypical adenoma (AA).

Aberrant right subclavian artery ("arteria lusoria") without the known associated nerve anomaly: an "anomaly of the anomaly"? A clinical case and review of the literature

The "non-recurrent" course of the inferior laryngeal nerve (ILN) is an anatomical variant which must be borne in mind during thyroid surgery. The "non-recurrent" course of the ILN on the right side is associated with the aberrant right subclavian artery (arteria lusoria), and, on the left, is described in situs viscerum inversus. We present a case in which the "arteria lusoria" was not associated with the non-recurrent right ILN. The aims of this paper are to report this "anomaly of the anomaly" to surgeons who may be unaware of it on the one hand and on the other to emphasize that this is the only case so far reported in the literature. Moreover we proposed to explain embryologically these unexpected findings.

Estrogen and thyroid cancer is a stem affair: A preliminary study

Gender influences Papillary Thyroid Cancer (PTC) with an incidence of 3:1 when comparing women to men with different aggressiveness. This gender discrepancy suggests some role of sex hormones in favoring the malignant progression of thyroid tissue to cancer. Estrogens are known to promote Stem Cell self-renewal and, therefore, may be involved in tumor initiation. The goals of these studies are to investigate the underlying causes of gender differences in PTC by studying the specific role of estrogens on tumor cells and their involvement within the Cancer Stem Cell (CSC) compartment. Exposure to 1nmoll^-1 Estradiol for 24h promotes growth and maintenance of PTC Stem Cells, while inducing dose-dependent cellular proliferation and differentiation following Estradiol administration. Whereas mimicking a condition of hormonal imbalance led to an opposite phenotype compared to a continuous treatment. In vivo we find that Estradiol promotes motility and tumorigenicity of CSCs. Estradiol-treated mice inoculated with Thyroid Cancer Stem Cell-enriched cells developed larger tumor masses than control mice. Furthermore, Estradiol-pretreated Cancer Stem cells migrated to distant organs, while untreated cells remained circumscribed. We also find that the biological response elicited by estrogens on Papillary Thyroid Cancer in women differed from men in pathways mediated. This could explain the gender imbalance in tumor incidence and development and could be useful to develop gender specific treatment of (PTC).

Igf-I influences everolimus activity in medullary thyroid carcinoma

CONTEXT

Medullary thyroid carcinoma (MTC) is a rare tumor originating from thyroid parafollicular C cells. It has been previously demonstrated that insulin-like growth factor I (IGF-I) protects MTC from the effects of antiproliferative drugs. Everolimus, an mTOR inhibitor, has shown potent antiproliferative effects in a human MTC cell line, TT, and in two human MTC primary cultures.

OBJECTIVE

To verify whether IGF-I may influence the effects of everolimus in a group of human MTC primary cultures.

DESIGN

We collected 18 MTCs that were dispersed in primary cultures, treated without or with 10 nM-1 μM everolimus and/or 50 nM IGF-I. Cell viability was evaluated after 48 h, and calcitonin (CT) secretion was assessed after a 6 h incubation. IGF-I receptor downstream signaling protein expression profile was also investigated.

RESULTS

Everolimus significantly reduced cell viability in eight MTC [by ~20%; P < 0.01 vs. control; everolimus-responders (E-R) MTCs], while cell viability did not change in 10 MTCs [everolimus-non-responders (E-NR) MTCs]. In E-R MTCs, IGF-I blocked the antiproliferative effects of everolimus that did not affect CT secretion, but blocked the stimulatory effects of IGF-I on this parameter. IGF-I receptor downstream signaling proteins were expressed at higher levels in E-NR MTC as compared to E-R MTCs.

CONCLUSION

IGF-I protects a subset of MTC primary cultures from the antiproliferative effects of everolimus and stimulates CT secretion by an mTOR mediated pathway that, in turn, may represent a therapeutic target in the treatment of aggressive MTCs.

A very rare bilateral adrenal tumor

We report a case of very rare adrenal tumor. A 54-year-old patient was classified as affected by bilateral adrenal incidentaloma that surprisingly, on histology resulted solitary fibrous tumors. Solitary fibrous tumor (SFT) is an uncommon mesenchymal neoplasm. Only five cases of localization of SFT in adrenal gland are reported in the literature, while the frequency of retroperitoneum localization is more frequent, about 30 cases. Immunohistochemically, SFT can be positive for CD34 antigen, vimentin, CD99, and bcl-2 and usually negative for cytokeratins, chromogranin A, NSE, neurofilaments, synoptophysin, and S-100. Surgical excision remains the main treatment in fact the recurrence is locoregional and correlated with positive margins due to incomplete excision, while distant metastases are correlated with atypical or malignant features.

Incidental medullary thyroid microcarcinoma revealed by mild increase of preoperative serum calcitonin levels: therapeutic implications

To investigate whether further, diagnostic procedures should be recommended in patients with slight increase of preoperative serum basal calcitonin (bCT) levels in whom surgical treatment can be recommendable. Fourteen consecutive patients with nodular thyroid disease underwent thyroidectomy in our center for suspected medullary thyroid microcarcinoma (MTC) because their serum bCT levels were slightly higher than the upper limit of normal range. Serum bCT was measured by radioimmunoassay, normality range = 0-20 ng/L. Surgical specimens were examined by the same pathologist using histologic and immunohistochemistry techniques. An extensive search for parafollicular C-cell hyperplasia (CCH) and/or microscopic MTC foci was performed. At preoperative ultrasound, a single thyroid nodule was depicted in three patients while a multinodular goiter in 11. The bCT values ranged between 24.4 and 94.6 ng/L, median 42.2 ng/L while the pentagastrin-stimulated CT (sCT) values by pentagastrin test ranged between 61.5 and 1,262 ng/L, median 245.0 ng/L. Total thyroidectomy was performed in 13 patients, and lobectomy in the other one; central node dissection was also performed in eight cases. At histology, MTC was diagnosed in nine patients (64.3 %), showing a median maximum diameter of 6.1 mm (range, 1.5-17 mm); CCH was diagnosed in the other five patients (35.7 %). The pentagastrin stimulation test was obtained in all patients. It is worth noting that a very high increase of sCT >100 ng/mL was observed in 5/9 patients with MTC and in 2/4 patients with HCC, therefore suggesting the absence of a relationship between the entity of response to pentagastrin test with a specific pathology (MTC vs. HCC). In six patients, the MTC was the nodule on which preoperative FNAC had been performed, while in other three patients preoperative FNAC had been performed on a different nodule from the MTC. Based on our experience, in case of the pentagastrin stimulation test with sCT <100 ng/L and a single nodule, the CT assay on FNAC may be useful, subsequently lobectomy with definitive histological diagnosis is recommended. In case of the Pg test with sCT <100 ng/L and bilateral goiter, total thyroidectomy with histological diagnosis is recommended. In this way, as for the surgical procedure, total thyroidectomy is recommended in cases of bilateral goiter, while lobectomy can be offered for cases with single nodes with serum dosage of bCT in the strict follow up. In case of the pentagastrin stimulating test with sCT <100 ng/L and bilateral goiter, total thyroidectomy with histological diagnosis is recommended.

Circulating cell-free DNA, SLC5A8 and SLC26A4 hypermethylation, BRAF(V600E): A non-invasive tool panel for early detection of thyroid cancer

PURPOSE

In the latest years, high levels of circulating cell-free DNA (cf-DNA) have been found to be associated with cancer diagnosis and progression, and cf-DNA has become a potential candidate as biomarker for tumor detection. cf-DNA has been investigated in plasma or serum of many tumor patients affected by different malignancies, but not yet in thyroid cancer (TC). Furthermore, in TC cells the capability to metabolize iodine is frequently lost. SLC5A8 and SLC26A4 genes are both involved in the iodine metabolism, and SLC5A8 hypermethylation status is associated with the BRAF(V600E) mutation, which is the most frequent genetic event underlying the development of papillary TC. The aim of our study is the development of a new non-invasive tool for the diagnosis and prognosis of TC based on cf-DNA, SLC5A8 and SLC26A4 hypermethylation, and BRAF(V600E) analysis.

METHODS

cf-DNA was measured by quantitative real-time PCR in nine cases of anaplastic thyroid cancer (ATC), 58 medullary thyroid cancers (MTC), five of synchronous medullary and follicular thyroid cancers (SMFC), 23 follicular adenomas (FA), 86 papillary thyroid cancers (PTC). A control group of 19 healthy subjects was taken. Moreover, in the PTC group we analyze the state of hypermethylation of SLC5A8 and SLC26A4, BRAF(V600E) mutation, and their involvement in the loss of function of the thyroid.

RESULTS

cf-DNA showed a high ability to discriminate healthy individuals from cancer patients. cf-DNAALU83 and cf-DNAALU244 values were significantly correlated with the histological type of TC (P-value < 0.0001). A significant increase in the amount of cf-DNAALU83 and cf-DNAALU244 when methylation occurs was observed (P-value = 0.02). A correlation between BRAF(V600E) and cf-DNAALU244/ALU83 was also found (P-value = 0.02).

CONCLUSIONS

According to our experimental results, the panel including cf-DNA, SLC5A8 and SLC26A4 hypermethylation, and BRAF(V600E) analysis appears easy, reproducible, and non-invasive for the diagnosis on TC. Its possible implication in clinical setting remains to be elucidated.

BRAF(K601E) mutation in a patient with a follicular thyroid carcinoma

BACKGROUND

BRAF mutations, the most common genetic alteration associated with papillary thyroid carcinoma (PTC), have never been associated with follicular thyroid carcinoma (FTC) except for one possible case, which, however, had some cellular features of the follicular variant of PTC. Here, we present a patient with a BRAF mutation within a FTC.

SUMMARY

A 78-year-old man presented with a nodular lesion 8 cm in size in the right thyroid lobe, coexisting with a goiter. Fine-needle aspiration samples were obtained for cytology, immunocytology, and molecular analysis. Immunoblot analysis on thyroid tissues was performed to evaluate the most important tumor activating pathways. Cytology was consistent with "follicular neoplasia" (negative for galectin-3 immunostaining); molecular analysis on the cytology sample detected a K601E mutation in the exon 15 of the BRAF gene. After total thyroidectomy with lymph-node dissection, the diagnosis of FTC was established by histopathological examination. The BRAF(K601E) mutation was confirmed in DNA obtained from different areas of the FTC. In addition, an activating mutation (E545A) in the PKI3CA oncogene was found in the FTC. As expected, immunoblot analysis showed activation of the PI3K/Akt pathway.

CONCLUSION

This article describes what may be the first case of a classical FTC carrying a BRAF mutation. Unlike the most common BRAF mutation seen in PTC carcinoma (BRAF(V600E)), this patient's mutation was a BRAF(K601E) mutation that previously has been associated with some cases of the follicular variant of PTC. The BRAF(K601E) mutation should be included in the spectrum of genetic alterations in FTC.

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.

Combined RET and Ki-67 assessment in sporadic medullary thyroid carcinoma: a useful tool for patient risk stratification

OBJECTIVE

Medullary thyroid carcinoma (MTC) derives from the parafollicular C cells, being sporadic in 75% of cases and familial in 25%, due to RET proto-oncogene germinal mutations. In sporadic forms, stage at diagnosis is the most important negative prognostic factor. The aim of this study was to evaluate the prognostic impact of molecular and immunohistochemical markers in sporadic MTC.

DESIGN AND METHODS

We studied 60 patients with sporadic MTC. For each case, we sought RET somatic mutations in the primary cancer and in lymph node metastases. The primary cancer also underwent immunohistochemical examination for Ki-67.

RESULTS

A somatic RET mutation was found in 38% of patients, being M918T in 52% of them. We observed a statistically significant association between RET mutations and male gender (P<0.01), tumor size (P<0.05), lymph nodes (P<0.05) and distant metastases (P<0.001), advanced stage (P<0.05), increased risk of persistent disease (P=0.01), and low overall survival (P<0.01). High Ki-67 levels were similarly associated with extra-thyroid spread (P<0.05), lymph nodes (P<0.05) and distant metastases (P<0.001), advanced stage (P=0.01), and low overall survival (P=0.01). Combining somatic RET analysis with Ki-67 assessment seems to be useful for increasing the specificity of Ki-67 assessment alone and identifying patients with a more aggressive cancer: in our series, only the patients who died during the follow-up had both a somatic RET mutation and a Ki-67 expression level >50 cells/mm(2).

CONCLUSIONS

The combined evaluation of RET and Ki-67 could act as an adjuvant prognostic marker useful for ameliorating the initial risk stratification of patients with sporadic MTC.

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

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.

BRAF in primary and recurrent papillary thyroid cancers: the relationship with (131)I and 2-[(18)F]fluoro-2-deoxy-D-glucose uptake ability

OBJECTIVE

BRAF V600E is a potential marker of poor prognosis in papillary thyroid cancers (PTC). In a previous report, we showed that recurrent PTC with no radioiodine ((131)I) uptake are frequently associated with BRAF mutations, a low expression of thyroid-related genes and a high expression of glucose type-1 transporter gene.

AIM

The aim of the present study was to assess BRAF status in a large series of recurrent PTC patients, considering paired primary and recurrent cancers. The BRAF genotype was correlated with the ability to concentrate (131)I and/or 2-[(18)F]fluoro-2-deoxi-d-glucose ((18)F-FDG) in the recurrent cancers, serum markers of recurrence, and patient outcome.

DESIGN AND METHODS

We studied 50 PTC patients with recurrent cervical disease submitted to a re-intervention, followed up in median for 9 years. BRAF analysis was conducted by direct sequencing and mutant allele-specific PCR amplification. In 18 cases, molecular analysis was also assessed in the primary cancer. Out of 50 patients, 30 underwent (18)F-FDG-positron emission tomography-computed tomography.

RESULTS

BRAF V600E-positive recurrent patients were found (131)I-negative in 94% of cases (P<0.001); 73% of the cancers carrying BRAF V600E were both (131)I-negative and (18)F-FDG positive. In paired primary and recurrent PTC, BRAF V600E was observed in 79% of the primary cancers and 84% of their recurrences. Three patients with (131)I-negative and BRAF V600E-positive recurrent cancers deceased during follow-up.

CONCLUSIONS

BRAF mutations are more common in thyroid recurrences with no (131)I uptake than in (131)I-positive cases. They are correlated with the ability to concentrate (18)F-FDG, and they can appear, albeit rarely, as a de novo event in the course of PTC recurrences.

Can we avoid inadvertent parathyroidectomy during thyroid surgery?

OBJECTIVES

To identify risk factors of inadvertent parathyroidectomy (IP) during thyroid surgery with the aim of decreasing the incidence of this unpleasant complication and to evaluate the impact on temporary and permanent hypocalcaemia following bilateral thyroidectomy.

PATIENTS AND METHODS

All consecutive thyroid surgical procedures performed at the Special Surgical Pathology Department of Padova General Hospital and Padova University during one year (January-December 2005) were retrospectively reviewed. Demographic data as well as data on diagnosis, operative reports, pathology findings, and postoperative serum calcium values were collected. A total of 882 patients (F=685 M=197) were included in the study. The patients were divided into 2 groups: those with IP and those without IP, and their data were compared to find factors affecting the occurrence of IP. The impact of IP on residual early and late postoperative parathyroid function was assessed. Hypercalcaemic (calcium level below 2.10 mMol/L) patients were followed from 1 week to 3 years.

RESULTS

Seventy of 882 patients (7.9%) were found to have IP. In 11 cases (16% of IP cases and 1.2 % of entire series) the parathyroid glands were completely intrathyroidal. The results of bivariate analysis showed young age (p=0.037), malignant disease (p<0.0001), total thyroidectomy with lymph node dissection (p<0.0001), low weight of thyroid specimen (p<0.0001), and non-visualisation of any parathyroid gland at operation (p<0.0001) as predictive factors for IP. Multivariate analysis revealed significant correlation between IP and malignant disease (p=0.004), and between lymph node dissection and permanent postoperative hypocalcaemia (p=0.018). The incidence rate of transient and permanent hypocalcaemia was higher in IP than in those without. The mean diameter of excised parathyroid glands was 3.2 mm, suggesting more extended or difficult surgical procedures.

CONCLUSION

IP is not uncommon during thyroidectomy and is associated with a higher, though not statistically significant, incidence of transient and permanent postoperative hypocalcaemia. Malignant disease, lymph node dissection, non-visualization of any parathyroid gland at operation and younger age seem to be risk factors and should be considered by the surgeon. Further efforts must be taken to reduce the incidence beginning by avoiding parathyroid fragmentation.

Characterization of a novel complex BRAF mutation in a follicular variant papillary thyroid carcinoma

INTRODUCTION

Activating mutations of the BRAF oncogene are frequently detected in papillary thyroid carcinoma (PTC) and have been associated with a worse prognosis. The amino acid substitution V600E accounts for 90% of all oncogenic BRAF mutations and is typically detected in classic PTCs, whereas other less frequent BRAF mutations seem to be associated with other PTC histotypes.

CASE

Screening for activating BRAF mutations in a series of 83 PTCs identified the most common V600E mutation in 39 cases (histologically, 38 classic PTCs and 1 sclerosing variant PTC) and a complex in-frame mutation involving amino acids V600-S605 in a stage III multicentric follicular variant PTC, occurring in a 50-year-old female patient, who was affected by hypothyroidism in autoimmune thyroiditis and had a family history of PTC and autoimmune thyroiditis. Since the identified BRAF mutation was novel in the literature, bioinformatic modeling was performed to predict its impact on BRAF activity. Although the mutation resulted in loss of a phosphorylation site in the activation loop of BRAF, it was predicted to increase BRAF kinase activity by mimicking an activating phosphorylation.

CONCLUSIONS

This study, which reports a new BRAF mutation, highlights the usefulness of bioinformatic modeling in the prediction of functional effects of new mutations and indicates that mutation-specific screening tests might miss some rare BRAF mutations. These facts should be taken into consideration in the molecular diagnosis of thyroid cancer and in the design of therapeutic protocols based on inhibitors of the BRAF pathway.

[The surgical treatment of the nodular goiter]

BACKGROUND

The simple nodular goiter, the etiology of which is multifactorial, encompasses the spectrum from the incidental asymptomatic small solitary nodule to the large intrathoracic goiter, causing pressure symptoms as well as cosmetic complaints. The mainstay in the diagnostic evaluation is related to functional and morphological characterization with serum TSH and (some kind of) imaging. Because malignancy is just as common in patients with a multinodular goiter as patients with a solitary nodule, the increasing use of fineneedle aspiration biopsy (cytology) is supported Its management is still the cause of considerable controversy. Prevalence of nodular goiter and results of surgical treatment in a large series of patients operated on at our center are reported.

METHODS

From January to December 2004, 1009 out of 1580 patients admitted to our Center underwent surgical treatment for thyroid disease.

RESULTS

Nodular goiter accounted for 80% of the whole series. More in detail, toxic multinodular goiter was found in 13.5% of the patients, euthyroid multinodular goiter in 46.6%, single hyperplastic nodule in 2.3%, follicular lesion in 14%, Plummer's adenoma in 4.4%, relapsing goiter in 2.6% and thyroid cyst in 0.12%. Thyroid lobectomy was carried out in 20.8% of patients, while the remaining 79.2% underwent to total thyroidectomy. A carcinoma was incidentally found in 7.6% of the multinodular goiters.

CONCLUSIONS

Surgery should be advocated for the treatment of thyroid nodules whenever a patient presents with either pressure symptoms, hyperthyroidism or follicular cytology. Serum TSH measurement, ultrasounds and fine needle aspiration cytology are the main diagnostic tools. Bilateral surgical exploration of the gland should be always carried out to assess the extension of the disease. Total or near total thyroidectomy in order to minimize the risk of recurrent nerve palsy and hypoparathyroidism represents the treatment of choice for bilateral goiter. Thyroid lobectomy with frozen section should be limited to unilateral nodular goiter.

Papillary thyroid carcinoma: 35-year outcome and prognostic factors in 1858 patients

BACKGROUND AND AIM

Papillary thyroid carcinoma (PTC) is universally regarded as a curable malignancy with a favorable prognosis. However, a minority of patients may present, or subsequently develop, locoregional and distant metastases that may adversely affect survival. The value of the various staging methods is complicated by different approaches to diagnostic, therapeutic and follow-up strategies. We aimed at assessing the prognostic factors and survival rate in a large cohort of patients treated and followed up in the same center.

MATERIALS AND METHODS

A total of 1858 patients with PTC operated on by the same surgeon, and followed in the same center over a period of 35 years, were included. Total thyroidectomy was performed in the majority of patients after I-131 diagnostic scans and thyroglobulin assays. When the latter 2 were positive, therapy with I-131 was given. Follow-up was performed periodically and further therapy doses were administered when necessary. All patients were maintained on life-long thyroxine.

RESULTS

Ninety-three patients (5%) developed evidence of locoregional or distant metastases after an average follow-up period of 7.9 years (range 1.53-30.5 years). Univariate analysis showed all variables (except for gender) to be significantly correlated with disease recurrence and survival. Multivariate analysis showed 4 variables to be significant and independent prognostic factors: patient age at first treatment, extent of disease, extent of surgery, and the presence of I-131 positive metastases.

DISCUSSION AND CONCLUSION

Our data agree with other scoring systems in that patient age at first treatment and the extent of disease are significant and independent prognostic factors. However, and at variance with other methods, we found that the extent of primary surgery and the presence of I-131 positive or negative metastases have similar prognostic significance. In high risk patients, total thyroidectomy and lymphadenectomy followed by I-131 treatment and TSH-suppressive hormonal therapy are recommended.

Contribution of SLN investigation with 99mTc-nanocolloid in clinical staging of thyroid cancer: technical feasibility

PURPOSE

It is a matter of controversy whether prophylactic lymph node dissection improves prognosis and survival in papillary thyroid carcinoma (PTC) patients without suspicion of lymph node metastases either clinically or on ultrasonography. It is possible that in such patients the use of lymphatic mapping and sentinel lymph node (SLN) biopsy, as are employed for other tumours, will be of assistance. The aim of this study was to evaluate the feasibility of preoperative 99mTc-nanocolloid lymphoscintigraphy and an intra-operative SLN procedure in the management of PTC patients.

METHODS

Twenty-five consecutive patients were entered in the study between April 2005 and October 2005. All had a preoperative diagnosis of malignancy obtained by fine-needle aspiration cytology (FNAC), without clinical or ultrasonographic evidence of loco-regional lymph node involvement. Patients underwent preoperative lymphoscintigraphy after the injection of 99mTc-nanocolloid [median 6 MBq (range 4-9 MBq) in 0.1-0.2 ml saline injected intratumorally under ultrasound guidance] and an intra-operative SLN procedure using a hand-held gamma probe. Surgery was performed by the same surgeon in all patients.

RESULTS

Preoperative lymphoscintigraphy identified at least one SLN in all patients. During surgery, using the gamma probe, the surgeon was able to find at least one SLN in all cases. A good correlation was found between preoperative imaging and probe results. Metastasis was found in at least one SLN in 12 (48%) patients. In seven (28%) patients the involved SLN was the most radioactive SLN, while in five (20%) patients a less radioactive SLN was involved by malignancy. Ten of these 12 patients had only micrometastases (<2 mm). Micrometastases were found in the most radioactive SLN in six cases and in less radioactive SLNs in four cases, while in two patients more lymph nodes visualised at lymphoscintigraphy ipsilateral to the primary tumour were sites of metastasis.

CONCLUSION

The rate of nodal involvement was very high in our series: in 48% of patients at least one metastatic lymph node was found. From a technical point of view the intra-operative SLN procedure in PTC patients was easy to perform, without major intra-operative complications. Our promising preliminary experience needs to be confirmed in larger series of patients series with longer follow-up.

Familial nonsyndromic pheochromocytoma

Judging from recent data, heritable forms account for 30-40% of pheochromocytomas. The molecular basis for the familial pheochromocytoma has been largely elucidated and the role of germline mutation of the VHL, RET, SDHB, and SDHD genes has been established. However, on genotyping a group of 172 sporadic or familial pheochromocytomas, we characterized four unrelated probands with familial pheochromocytomas without any sequence variants of RET (exons 8, 10, 11, 13, 14, 15, and 16) or the entire coding sequence of VHL, SDHB, SDHC, SDHD, and EGLN3 (exon-intron boundaries included). The proband of family 1 is a man who had a bilateral pheochromocytoma at the age of 32 and a local recurrence at the age of 48 years. His brother died of malignant pheochromocytoma and his nephew died suddenly of an undiagnosed pheochromocytoma. The proband of family 2 is a female who had a 5-cm benign adrenal pheochromocytoma at the age of 34 years, while her cousin (maternal branch) had a monolateral pheochromocytoma at the age of 42 years. No other tumors had been reported in either family. The proband of family 3 is a female who had a bilateral pheochromocytoma at the age of 66 years. Her sister had a bilateral pheochromocytoma and breast cancer at the age of 54 years. Several other tumors were recorded in this family, including laryngeal cancer, leukemia, and a case of medullary thyroid carcinoma (MTC) in one brother. MTC was naturally ruled out in the proband and her sister. In family 4, the proband was a female who had a bilateral pheochromocytoma at the age of 46 years and a local recurrence a few years later, with liver metastases from the pheochromocytoma. Her brother had a monolateral benign pheochromocytoma. The proband also had a melanoma and bilateral renal cysts. This case revealed a VHL sequence variant IVS2+43 A>G, which was also found in one other unrelated sporadic pheochromocytoma. VHL mRNA integrity is currently being evaluated. The proband had no cerebellar or spinal NMR findings or retinal alterations. In family 5, the proband was a female who had a right adrenal pheochromocytoma at the age of 50 years and a breast cancer at 49 years of age. Her mother had had a right adrenal pheochromocytoma at 61 years of age. Although other molecular mechanisms, such as particular variants in untranslated regions or partial gene deletions, cannot be ruled out, we think finding families with nonsyndromic pheochromocytoma without any RET, VHL, SDHB, SDHC, SDHD, or EGLN3 mutation may argue in favor of the presence of other pheochromocytoma susceptibility genes.

Natural history, diagnosis, treatment and outcome of medullary thyroid cancer: 37 years experience on 157 patients

AIM

The analysis of a 37-year retrospective study on diagnosis, prognostic variables, treatment and outcome of a large group of medullary thyroid cancer (MTC) patients was conducted, in order to plan a possible evidence-based management process.

METHODS

Between Jan 1967 to Dec 2004, 157 consecutive MTC patients underwent surgery in our centre: 60 males and 97 females, mean age 47.3 years (range 6-79). Total thyroidectomy was performed in 143 patients (91.1%); central compartment (CC) node dissection (level VI) in 41 patients; central plus lateral compartment (LC) node dissection (levels II, III, and IV) in 82 patients. Subtotal thyroidectomy was initially performed in 14 cases: 10 of them were re-operated because of persistence of elevated serum calcitonin levels.

RESULTS

After a median post-surgical follow-up of 68 months (range 2-440 months), 42.9% of patients were living disease-free, 39.8% were living with disease, 3.1% were deceased due to causes different from MTC, and 3.2% were deceased due to MTC. The overall 10-year survival rate was 72%. At uni-variate statistical analysis (a) patient's age at initial treatment (>45 years; >/=45 years), (b) sporadic vs. hereditary MTC, (c) disease stage, and (d) the extent of surgical approach resulted as significant variables. Instead, at multivariate statistical analysis, only (a) patient's age at initial diagnosis, (b) disease stage, and (c) the extent of surgery resulted as significant and independent prognostic variables influencing survival.

CONCLUSION

The presence of lymph node and distant metastases at first diagnosis significantly worsened prognosis and survival rate in our series. Early diagnosis of MTC is very important, allowing complete surgical cure in Stages I and II patients. Due to the relatively bad prognosis of MTC, especially for disease Stages III and IV, it appears reasonable to recommend radical surgery including total thyroidectomy plus CC lymphoadenectomy as the treatment of choice, plus LC lymphoadenectomy in patients with palpable and/or ultrasound enlarged neck lymph nodes.

Papillary thyroid microcarcinoma (PTMC): prognostic factors, management and outcome in 403 patients

AIM

To investigate an "optimal" therapeutic management of patients with papillary thyroid microcarcinoma (PTMC).

METHODS

We evaluated a group of 403 consecutive patients affected by PTMC operated on by the same surgeon. Prognostic factors were evaluated by uni- and multivariate statistical analysis.

RESULTS

After a mean follow-up of 8.5 years, 372 patients were living without disease (undetectable serum thyroglobulin levels), 24 patients were living with disease (increased serum thyroglobulin levels), 6 patients were deceased due to causes different from thyroid cancer, and 1 patient was deceased due to metastatic thyroid cancer. No statistically significant prognostic factor was found at uni- and multivariate analysis. However, it is worth noting that in patients with a larger primary tumour (size> or =5mm) and treated by partial thyroidectomy alone, the prevalence of recurrent disease was higher than in patients treated by total thyroidectomy and (131)I administration.

CONCLUSION

It appears reasonable to perform total thyroidectomy (possibly associated with central compartment node dissection), (131)I whole body scan (followed by (131)I therapy when necessary) and TSH-suppressive hormonal therapy in patients with PTMC.

Locally advanced differentiated thyroid carcinoma: a 35-year mono-institutional experience in 280 patients

AIM

Debate exists in the literature about the optimal treatment to be adopted in patients with locally advanced differentiated thyroid carcinoma. We aimed to better define the most appropriate diagnostic and therapeutic protocol for this type of tumour.

METHODS

The clinical and histopathological records of 280 consecutive patients with locally advanced differentiated thyroid carcinoma, studied and operated on by the same surgical team in the period between 1967 and 2002, were reviewed.

RESULTS

With regard to overall survival, at univariate statistical analysis, the patient's age at diagnosis (threshold, 45 years), primary tumour size, local cancer extension at diagnosis (subtypes of T4), extent of thyroidectomy, performance of lymph node dissection and performance of post-surgical external radiotherapy were found to be significant prognostic variables. With regard to the appearance of recurrent disease during follow-up, at univariate statistical analysis, the patient's age at initial diagnosis (threshold, 45 years), primary tumour size, local cancer extension at diagnosis (subtypes of T4), extent of thyroidectomy, performance of lymph node dissection, presence of metastatic lymph nodes, performance of post-surgical 131I therapy and performance of post-surgical external radiotherapy were found to be significant prognostic variables. At multivariate statistical analysis, the patient's age at initial diagnosis, extent of tumour, extent of thyroidectomy and performance of lymph node dissection were the only independent prognostic variables.

CONCLUSIONS

In our experience, an aggressive surgical approach at first diagnosis appears to offer a better prognosis in terms of both overall survival and disease-free time interval in patients with locally advanced differentiated thyroid carcinoma, especially those over 45 years of age.

Thyroid intrafollicular neoplasia (TIN) as a precursor of papillary microcarcinoma

BACKGROUND

The aim of this study was to identify a spectrum of morphological changes from benign reactive follicles to suspected thyroid intrafollicular neoplasia (TIN) and papillary microcarcinoma observed in different pathological processes of the thyroid gland.

CASE SERIES

In a retrospective study on a total of 105 cases, occult or incidental thyroid papillary microcarcinoma was found in association with multinodular goiter (52%), chronic thyroiditis (19%), follicular adenoma (19%), parathyroid neoplasia (5%), and no evident thyroid pathology (5%).

RESULTS

Atypical follicles are described in various pathological conditions correlating with lymphoid inflammatory infiltration, stromal sclerosis, and hyperplastic or neoplastic follicular nodules. The histological pattern of papillary carcinoma is compared with morphological changes ranging from atrophic and/or reactive thyroid follicles, potential intrafollicular thyroid neoplasia (TIN) and papillary microcarcinoma.

CONCLUSIONS

The atypical features of follicular epithelial areas make up a wide spectrum that starts with the dispersion of nuclear chromatin. Low- and high-grade TIN may represent a cytological marker of dysplastic lesions and precursors of thyroid papillary carcinoma when it is still in an early intrafollicular or pre-invasive stage in various pathological processes of the thyroid.

Natural history, diagnosis, treatment and outcome of papillary thyroid microcarcinoma (PTMC): a mono-institutional 12-year experience

The clinical and histopathological records of 149 consecutive patients with papillary thyroid microcarcinoma (PTMC), homogeneously studied and operated on by the same surgeon in the period 1990 to 2001, were reviewed. After a mean 6.5-year follow-up, three cases of loco-regional recurrence (2%) were observed. These three patients had all undergone partial thyroidectomy only and tumour relapse occurred in the residual thyroid tissue. No recurrence was observed in patients treated by total thyroidectomy and I. At variance with other reported series, no lymph node recurrence was observed in our series, in particular in the group of 23 patients with evidence of nodal metastases at initial diagnosis (three of whom were revealed by I scan after surgery). Therefore, a preventive effect of I treatment in our patient population can be hypothesized. However, prolonged follow-up will be necessary to clarify this. Due to the inability of current imaging modalities to select pre-operatively PTMC patients at risk for recurrence (presence of thyroid capsular invasion, multifocality and microscopic lymph node metastases), it appears reasonable to offer the patient total thyroidectomy when a pre-operative diagnosis of PTMC is reached. Moreover, the policy of our thyroid cancer centre is that, in these patients, post-surgical I scan should be obtained in order to detect unknown metastatic deposits, and I treatment should also be considered in patients with poor clinical and histopathological prognostic factors. In contrast, in patients operated on for benign thyroid disease and with delayed diagnosis of PTMC at definitive histopathological examination, re-operation might be avoided in the presence of unifocal disease without thyroid capsular invasion and with ultrasound-'normal' residual thyroid tissue. Close clinical and ultrasound follow-up is recommended, especially in patients who have undergone conservative surgery only.

The sentinel node procedure with Patent Blue V dye in the surgical treatment of papillary thyroid carcinoma

How far to extend the surgical treatment of papillary thyroid carcinoma (PTC) is still an open question. A contribution may come from intra-operative lymphatic mapping because, in other malignancies, the procedure has become an important aid in defining lymph node status. To assess the feasibility of using the sentinel lymph node (SLN) technique with the intratumoral injection of Patent Blue V dye to guide nodal dissection in PTC, 29 patients with a preoperative diagnosis of PTC and no clinical or ultrasonographic evidence of nodal involvement underwent cervicotomy and exposure of the thyroid gland, followed by Patent Blue V dye injection into the thyroid nodule. Total thyroidectomy was subsequently performed, resecting the lymph nodes at levels III, IV, VI and VII. The thyroid, SLN and the other lymph nodes were snap-frozen and submitted for both intra-operative and subsequent definitive pathological evaluation. Intra-operative lymphatic mapping located the SLN in 22/29 patients (75.9%) and the SLN revealed neoplastic involvement in 4/22 (18.2%); other lymph nodes were also positive in 2 cases. In the 18 patients whose SLNs were not metastatic, the other nodes were also disease-free. The SLN technique thus seems helpful in avoiding unnecessary lymph node dissection in PTC without spread to the SLN.