An adrenal cortical adenoma with neuroendocrine-type granules mimicking pheochromocytoma.

Clinical and biochemical presentation of adrenal tumors may rarely conflict with their histologic features. In the present report, we describe a rare case of adrenal neoplasm clinically and biochemically labeled as pheochromocytoma which at histologic examination resulted adrenal cortical tumor. The neoplasm was examined with the electron microscope which revealed the presence of electron-dense neuroendocrine-type granules next to intracytoplasmic lipid droplets. The patient underwent laparoscopic left adrenalectomy which leads to normalization of 24 h urinary metanephrine and normetanephrine. This exceptional entity should be taken into consideration when the clinical and laboratory features conflict with the histological examination. The pathologist can clarify the mixed nature of the tumor by means of the identification of neuroendocrine granules at the electron microscope examination.

First report of benign track seeding after robot-assisted transaxillary thyroid surgery.

BACKGROUND: Robot-assisted transaxillary thyroidectomy is a well-established remote-access thyroid procedure that has been demonstrated to be as safe and effective as its time-honored conventional clamp-and-tie counterpart. However, it has been incriminated for a set of unprecedented complications that surgeons need to be aware of and deal with appropriately. PATIENT FINDINGS: The patient is a young woman who underwent robot-assisted thyroid lobectomy for a sizeable nodule that was reported as benign after fine-needle aspiration cytology. She presented 3 years later with subcutaneous nodules along the surgical track that were found to represent seeding of benign thyroid tissue. This is the first report of benign thyroid tissue seeding after a gasless transaxillary procedure. SUMMARY: Seeding along the surgical track is a potential complication of gasless remote-access thyroid surgery, even in case of benign disease, that surgeons need to be acquainted with. CONCLUSIONS: Surgeons should be aware of the potential for benign seeding after remote-access thyroid procedures. Accordingly, adequate precautions should be taken, patients should be counseled in this regard, and alternative medical strategies to control local seeding of thyroid tissue could be suggested.

DELAYED 131-I FIRST TREATMENT AFTER SURGERY HAS NO IMPACT ON THE MEDIAN TERM OUTCOME OF PATIENTS WITH INTERMEDIATE RISK DIFFERENTIATED THYROID CANCER.

Objective: In intermediate risk (IR) differentiated thyroid cancer (DTC) patients, selective use of radioiodine (131-I) for remnant ablation and/or as adjuvant therapy (RRA) is advocated. The recently suggested postoperative evaluation could delay the use of RRA. The aim of this study was to evaluate if a delayed RRA can worsen the clinical outcome of IR-DTC patients. Methods: Four hundred and fourteen consecutive IR-DTC patients were divided according to the time elapsed from surgery to RRA, <6 months (group A, 186/414 [44.9%]), or ≥6 months (group B, 228/414 [55.1%]). Clinical and biochemical data were collected, and clinical outcome was analyzed at the first evaluation (EV) after RRA (first-EV) and after a median of 6 years of follow-up (last-EV). Results: No difference in the clinical outcome of group A and B was found. Since a different activity of 131-I could have an impact on the outcome, we separately analyzed the groups according to the 131-I activity (low-activity group: 1,110 MBq/30 mCi [n = 320], and high-activity group: 3,700 MBq/100 mCi [n = 94]), further subdivided according to the time elapsed from surgery to RRA. No major differences were found in both the low- and high-activity groups when comparing the features of their subgroups A and B, as far as in their clinical outcome. Conclusion: The time elapsed between surgery and the first 131-I treatment does not influence the clinical outcome of IR-DTC patients. This finding allows a more relaxed attitude in the decision making process whether to perform the RRA in IR-DTC cases in which a selective use of 131-I is recommended. Abbreviations: ATA = American Thyroid Association; DTC = differentiated thyroid cancer; EV = evaluation; HR = high risk; 131-I = radioiodine; IR = intermediate risk; LR = low risk; rhTSH = recombinant human thyroid-stimulating hormone; RRA = radioiodine for remnant ablation; Tg = thyroglobulin; TgAb = thyroglobulin autoantibody; US = ultrasound.

Role of Prophylactic Central Compartment Lymph Node Dissection on the Outcome Of Patients With Papillary Thyroid Carcinoma and Synchronous Ipsilateral Cervical Lymph Node Metastases.

OBJECTIVE: Prophylactic central compartment lymph node dissection (pCCND) results in a higher percentage of surgical-related complications. To date, no evidence of the impact of pCCND on the clinical outcome of papillary thyroid carcinoma (PTC) patients with synchronous ipsilateral cervical lymph node metastases has been reported. METHODS: We evaluated all consecutive patients affected by PTC and synchronous ipsilateral cervical, but without evidence of central compartment, lymph node metastases. We selected 54 consecutive patients (group A) treated by total thyroidectomy, ipsilateral cervical lymph node dissection, and pCCND and 115 patients (group B) matched for sex, age at diagnosis, number and dimension of the metastatic lateral cervical lymph nodes, without pCCND. Clinical outcome after a median of 5 years and surgical-related complications were assessed. RESULTS: The two groups were completely similar in terms of clinical features. Clinical outcomes showed a higher percentage of biochemical and indeterminate but not structural response in group B. Group B required significantly more radioiodine treatments, but no difference was shown in the need to repeat surgery for recurrences. Conversely, the prevalence of permanent hypoparathyroidism was significantly higher in group A (14.8%) than in group B (4.3%). CONCLUSION: In PTC patients with synchronous ipsilateral cervical lymph node metastases, in absence of clinically evident lymph node metastases of the central compartment, performing pCCND does not improve the 5-year outcome in terms of structural disease, despite a greater number of 131I treatments. However, pCCND is severely affected by a higher percentage of permanent hypoparathyroidism, even in the hands of expert surgeons. ABBREVIATIONS: IQR = interquartile range; pCCND = prophylactic central compartment lymph node dissection; PTC = papillary thyroid carcinoma; Tg = thyroglobulin; US = ultrasound.

Diagnosis of post-surgical fine-needle aspiration biopsies of thyroid lesions with indeterminate cytology using HRMAS NMR-based metabolomics.

INTRODUCTION: Ultrasound examination coupled with fine-needle aspiration (FNA) cytology is the gold standard for the diagnosis of thyroid cancer. However, about 10-40% of these analyses cannot be conclusive on the malignancy of the lesions and lead to surgery. The cytological indeterminate FNA biopsies are mainly constituted of follicular-patterned lesions, which are benign in 80% of the cases. OBJECTIVES: The development of a FNAB classification approach based on the metabolic phenotype of the lesions, complementary to cytology and other molecular tests in order to limit the number of patients undergoing unnecessary thyroidectomy. METHODS: We explored the potential of a NMR-based metabolomics approach to improve the quality of the diagnosis from FNABs, using thyroid tissues collected post-surgically. RESULTS: The NMR-detected metabolites were used to produce a robust OPLSDA model to discriminate between benign and malignant tumours. Malignancy was correlated with amino acids such as tyrosine, serine, alanine, leucine and phenylalanine and anti-correlated with myo-inositol, scyllo-inositol and citrate. Diagnosis accuracy was of 84.8% when only indeterminate lesions were considered. CONCLUSION: These results on model FNAB indicate that there is a clear interest in exploring the possibility to export NMR metabolomics to pre-surgical diagnostics.

New insights in the molecular signature of advanced medullary thyroid cancer: evidence of a bad outcome of cases with double RET mutations.

BACKGROUND: The RET proto-oncogene is responsible for the pathogenesis of hereditary (98%) and sporadic (40%) medullary thyroid carcinoma (MTC). In sporadic MTC, somatic RET mutations are associated with a poor prognosis. OBJECTIVES: We looked at the genetic profile of patients with advanced and metastatic MTC. The correlation between these mutations and outcome was also investigated. METHODS: 70 patients with advanced and metastatic sporadic MTC were studied. Exons 10-11 and 13-16 of RET were analysed by direct sequencing. All cases were studied for RAS and the majority also for TERT mutations. RET/RAS-negative cases were analysed for other oncogene mutations. RESULTS: 64/70 cases (91.4%) showed a somatic mutation, while 6 (8.6%) were negative. Among the mutated cases, RET mutations, mainly M918T, were the most prevalent (93.8%). K- or H-RAS mutations were present in 6.2% of cases and were mutually exclusive with RET. No other mutations were found. Four tumours showed two RET somatic mutations. We found a complex somatic RET alteration in 6/60 (10%) RET-positive sporadic MTC cases. A positive correlation between a poor prognosis and the multiple number of RET mutations was found. CONCLUSIONS: This study showed a high prevalence of somatic RET mutations in advanced and metastatic MTCs. RAS mutations were present in a small percentage of cases and mutually exclusive with RET mutations. In a small number of cases, more than one RET mutation was present in the same tissue. RET double mutations and, to a lesser extent, also complex mutations showed a worse outcome.

Twenty years of lesson learning: how does the RET genetic screening test impact the clinical management of medullary thyroid cancer?

OBJECTIVE: Medullary thyroid carcinoma (MTC) is a rare disease that can be inherited or sporadic; its pathogenesis is related to activating mutations in the RET gene. DESIGN: This study describes our 20-year experience regarding RET genetic screening in MTC. PATIENTS AND METHODS: We performed RET genetic screening in 1556 subjects, 1007 with an apparently sporadic MTC, 95 with a familial form and 454 relatives of RET-positive patients with MTC. RESULTS: A germline RET mutation was found in 68 of 1007 (6·7%) patients with sporadic MTC, while 939 patients with MTC were negative for germline RET mutations. We then identified a total of 137 gene carriers (GC). These subjects initiated a clinical evaluation for the diagnosis of MEN 2. A total of 139 MEN 2 families have been followed: 94 FMTC, 33 MEN 2A and 12 MEN 2B. Thirty-three different germline RET mutations were identified. Codon 804 was the most frequently altered codon particularly in FMTC (32/94, 34%), while codon 634 was the most frequently altered codon in MEN 2A (31/33, 94%); MEN 2B cases were exclusively associated with an M918T mutation at exon 16. CONCLUSIONS: Our 20-year study demonstrated that RET genetic screening is highly specific and sensitive, and it allows the reclassification as hereditary of apparently sporadic cases and the identification of GC who require an adequate follow-up. We confirmed that FMTC is the most prevalent MEN 2 syndrome and that it is strongly correlated with noncysteine RET mutations. According to these findings, a new paradigm of follow-up of hereditary MTC cases might be considered in the next future.

A nonfunctioning parathyroid carcinoma misdiagnosed as a follicular thyroid nodule.

Parathyroid carcinoma (PC) is a rare endocrine malignancy. The tumor is mostly functioning, causing severe primary hyperparathyroidism, with high serum calcium and parathyroid hormone (PTH) levels. Nonfunctioning PC is extremely rare. We report a 50-year-old male patient who was referred to our Department for a right thyroid nodule, incidentally detected on carotid Doppler ultrasound scan, with a fine-needle aspiration cytology showing a follicular lesion. At the time of our evaluation, neck ultrasound showed a 1.3 cm right hypoechoic thyroid nodule with irregular margins and the absence of enlarged bilateral cervical lymph nodes. Thyroid function tests were normal. Serum calcium was normal and plasma PTH slightly above the upper limit of the normal range. The patients underwent right lobectomy. The intraoperative frozen-section pathological examination raised the suspicion of a PC. Definitive histology showed a markedly irregular infiltrative growth of the tumor with invasion of the thyroid tissue and cervical soft tissues. Immunostaining for thyroglobulin was negative, whereas staining for chromogranin A and PTH showed a strong reactivity. Based on the microscopic findings and the immunohistochemical profile, the tumor was diagnosed as a PC. Postoperative serum calcium and phosphate levels were in the normal range. One month after surgery, serum calcium and PTH were normal. Neck ultrasound and total body computed tomography scan were negative for local and metastatic disease. Eight months later, serum calcium was normal and plasma PTH level remained around the upper limit of normal range. Neck ultrasound did not show any pathological lesions. This is the first case of a nonfunctioning sporadic PC misdiagnosed prior of surgery as a follicular thyroid nodule. The parathyroid nature of the neck lesion could not be suspected before surgery. Fine-needle aspiration cytology (FNAC) may fail to distinguish a parathyroid tumor from a benign thyroid nodule because at FNAC, parathyroid and thyroid lesions have some morphological similarities. Histological criteria are not always sufficient for the differential diagnosis, which can definitely be established using immunohistochemistry.

Neoadjuvant treatment with lenvatinib and pembrolizumab in a BRAF V600E-mutated anaplastic thyroid cancer: a case report.

Background: Tyrosine kinase inhibitors (TKIs) and immunotherapy have been proposed for advanced metastatic anaplastic thyroid cancer (ATC). We report a case of BRAF V600E-mutated ATC in which lenvatinib (L) plus pembrolizumab (P) enabled neoadjuvant treatment. Case presentation: A male patient aged 65 years presented with a rapidly enlarging left latero-cervical mass. Fine needle aspiration was suggestive of ATC. Surgical consultation excluded radical surgery. While awaiting molecular profile analysis and considering the fast evolution of the disease, treatment with L and P was started. L was started at a dose of 14 mg daily, while P was started at the standard regimen (200 mg every 3 weeks). After 1 month, computerized tomography showed a reduction in the mass with almost complete colliquative degeneration, and the carotid artery wall was free from infiltration. Radical surgery was performed. Histology confirmed papillary thyroid cancer (PTC) in the left lobe and ATC with extensive necrosis in the left latero-cervical lymph node metastasis. The margins were free of tumors (R0). A BRAF V600E mutation was present in both PTC and ATC. At the 1-year follow-up, the patient was free of disease. Conclusion: L and P in combination also appeared to be effective as a neoadjuvant treatment for BRAF V600E-mutated ATC. This combination treatment could be used when there is an opportunity for complete resection of the cancer, and as soon as possible. The intermediate dose of 14 mg of L appeared to be well tolerated and effective.

Nodal metastasis in noninvasive follicular thyroid neoplasm with papillary-like nuclear features (NIFTP).

The term noninvasive tumor with a follicular growth pattern and nuclear features of papillary thyroid cancer (NIFTP) is used to describe a tumor currently considered as a pre-malignant lesion for which a conservative therapeutic approach (i.e., lobectomy without radioiodine therapy) is strongly suggested. However, some patients with NIFTP and loco-regional or distant metastases have been already reported. We present an adult male patient with a final histological diagnosis of NIFTP and lymph node metastasis noted at post-therapy whole-body scintigraphy performed some days after radioiodine therapy.

Whole-exome sequencing of atypical parathyroid tumors detects novel and common genes linked to parathyroid tumorigenesis.

CONTEXT: Atypical parathyroid tumor (APT) represents a neoplasm characterized by histological features typical of parathyroid carcinoma (PC) but lacking local infiltration and/or distant metastasis, leading to uncertainty regarding its malignant potential. OBJECTIVE: To characterize the molecular landscape and deregulated pathways in APT. METHODS: Whole exome sequencing (WES) was conducted on 16 APTs. DNA from tumors and matched peripheral blood underwent WES using Illumina HiSeq3000. RESULTS: A total of 192 nonsynonymous variants were identified. The median number of protein-altering mutations was 9. The most frequently mutated genes included BCOR, CLMN, EZH1, JAM2, KRTAP13-3, MUC16, MUC19, and OR1S1. Seventeen mutated genes belong to the Cancer Gene Census list. The most consistent hub genes identified through STRING network analysis were ATM, COL4A5, EZH2, MED12, MEN1, MTOR, PI3, PIK3CA, PIK3CB, and UBR5. Deregulated pathways included the PI3 K/AKT/mTOR pathway, Wnt signaling, and extracellular matrix organization. Variants in genes such as MEN1, CDC73, EZH2, PIK3CA, and MTOR, previously reported as established or putative/candidate driver genes in benign adenoma (PA) and/or PC, were also identified in APT. CONCLUSIONS: APT does not appear to have a specific molecular signature but shares genomic alterations with both PA and PC. The incidence of CDC73 mutations is low, and it remains unclear whether these mutations are associated with a higher risk of recurrence. Our study confirms that PI3 K/AKT/mTOR and Wnt signaling represents the pivotal pathways in parathyroid tumorigenesis and also revealed mutations in key epigenetic modifier genes (BCOR, KDM2A, MBD4, and EZH2) involved in chromatin remodeling, DNA, and histone methylation.

Minor role of TP53 and TERT promoter mutations in medullary thyroid carcinoma: report of new cases and revision of the literature.

PURPOSE: Aims of this study were to investigate the prevalence of TP53 and TERT mutations in Medullary Thyroid carcinoma (MTC) and their role in inducing aggressiveness in positive cases. METHODS: We performed a literature search in PubMed to identify studies investigating the prevalence of TERT and TP53 mutations in MTC. We also included data on MTC cases (n = 193) obtained at our center and unpublished. The in-silico pathogenicity of the TP53 mutations has been evaluated by predictor tools. RESULTS: We identified a total of 25 and 11 published papers: all together 1280 cases have been investigated for the presence of TP53 mutations and 974 for TERT promoter mutation. Twenty-five out of 1280 (2%) cases had a TP53 mutation while only 3/974 MTC cases (0.3%) have been found to be positive for TERT promoter mutations. Among all, we identified 19 different TP53 mutations that in 12 cases were demonstrated to have an in silico predicted high pathogenic role and a high impact on protein function. Three non-sense and 4 probably not damaging mutations were also reported. The pathogenic role of the TERT promoter mutations has been previously in vitro determined. No correlation between TP53 and/or TERT mutations and aggressiveness of MTC has been demonstrated. CONCLUSION: The prevalence of TP53 and TERT promoter mutations is very low in MTC. The reported mutations are pathogenic in the majority of cases. Because of their rarity it is not possible to clarify if they play or not a role in the pathogenesis and/or aggressiveness of this specific thyroid tumor.

Molecular profiling of low-risk papillary thyroid carcinoma (mPTC) on active surveillance.

CONTEXT: The active surveillance (AS) program for papillary thyroid carcinoma (≤ 1 cm) at low-risk (mPTC) showed a low percentage of progression. OBJECTIVE: The aim of this study was to find a molecular signature of cases that showed disease progression during AS, which would allow their early identification. METHODS: We performed next generation sequencing of 95 fine needle aspiration cytology specimens from cases prospectively enrolled in the AS program to analyze key somatic driver alterations or gene fusions implicated in PTC tumorigenesis. TERT promoter analysis was performed using Sanger sequencing or droplet digital PCR. RESULTS: BRAF p.V600E was found in 66.3% (63/95) of mPTC and was the most common somatic alteration, followed by RAS oncogene mutations detected in 3.2% of mPTC (3/95: 2 NRAS and 1 KRAS) and gene fusions detected in 3.2% of mPTC (3/95: 1 RET-PTC1, 1 TFG-NTRK1, 1 ALK imbalance). No TERT promoter mutations (C228T and C250T) were found in the analyzed mPTC (84/95). The comparison between the molecular profile and the clinical outcome of the mPTC (stable versus progressive disease) showed no correlation (p-value=0.6) and did not identify a molecular signature able to identify progressive mPTC. CONCLUSIONS: The molecular profile of mPTC is like that of bigger PTC with the exception that none of them showed a TERT promoter mutation. The identification of the most common driver mutations, such as BRAF, RAS, or gene fusions, is not helpful for the early identification of mPTC that will show disease progression during follow-up in the AS program.

Identification of a Novel Non-V600E BRAF Mutation in Papillary Thyroid Cancer.

Papillary thyroid cancer (PTC) is a common endocrine malignancy, and its incidence is reported to be constantly increasing. BRAF mutation is detected in approximately 44% of PTCs, and the most common BRAF mutation is thymine (T) to adenine (A) missense mutation in nucleotide 1796 (T1796A, V600E). Although BRAFV600E represents 95% of all BRAF mutations, uncommon BRAF mutations have been reported in thyroid carcinomas and represent an alternative mechanism of BRAF activation with unclear clinical significance. We report a novel non-V600E mutation (c.1799_1812delinsAT, p.V600_W604delinsD), identified preoperatively with next-generation sequencing (NGS) on the material obtained with fine-needle aspiration cytology (FNAC) performed on a thyroid nodule cytologically suspicious for malignancy in a 35-year-old male patient. The presence of this new variant of BRAF mutation was subsequently confirmed in the postoperative phase by direct Sanger sequencing. In conclusion, we report a new non-V600E variant previously undetected in papillary thyroid cancer. In addition, this case report shows that the NGS technique on cytological tissue allows to detect the presence of rare mutations, thus increasing the diagnostic specificity of molecular analysis.

The 5th edition of WHO classification of tumors of endocrine organs: changes in the diagnosis of follicular-derived thyroid carcinoma.

The 5th edition of the World Health Organization (WHO) classification of endocrine tumors was released in 2022. Several novelties have been introduced concerning the nomenclature and histopathological diagnosis of follicular-derived thyroid neoplasms. Tumor types have been sharply classified according to prognostic risk categories into benign tumors, low-risk neoplasms and malignant neoplasms. A grading system for differentiated thyroid carcinomas has been implemented with the aim of improving the stratification of tumors. Particular attention has been paid to the molecular profile of well-differentiated histotypes. In this review, the main changes introduced by the latest edition of the WHO system are presented. The practical effects on the diagnostic pathology of thyroid tumors, along with the clinical implications expected with the new classification scheme, are critically discussed.

Ultrasound features and risk stratification system in NIFT-P and other follicular-patterned thyroid tumors.

OBJECTIVE: Noninvasive follicular thyroid neoplasm with papillary-like nuclear features (NIFT-P) is an encapsulated follicular variant of papillary thyroid carcinoma (PTC) with nonaggressive clinical behavior. However, since its diagnosis is exclusively possible after surgery, it represents a clinical challenge. Neck ultrasound (US) shows good sensitivity and specificity in suggesting malignancy in thyroid nodules. However, little information is available about its ability in identifying NIFT-P. DESIGN: The aim of this study was to evaluate the US features of NIFT-P, comparing them with other follicular-patterned thyroid tumors, and to test the ability of the main US risk stratification system (RSS) in identifying NIFT-P. METHODS: We retrospectively evaluated 403 consecutive patients submitted to thyroid surgery, with positive histology for at least 1 nodule being NIFT-P, follicular variant of PTC (FV-PTC), follicular thyroid carcinoma (FTC), or follicular adenoma (FA). RESULTS: The US features of NIFT-P (n = 116), FV-PTC (n = 170), FTC (n = 76), and FA (n = 90) were reported. Follicular variant of PTC and FTC more frequently showed irregular margins, presence of calcifications, "taller than wide" shape, and the absence of halo compared with NIFT-P. Furthermore, FTC and also FA were larger and more frequently hypoechoic than NIFT-P. Most cases (77%) showed an indeterminate cytology. Regardless of the US RSS considered, NIFT-P and FA were less frequently classified in the high-suspicious category compared with FV-PTC and FTC. CONCLUSIONS: Ultrasound features of NIFT-P are frequently superimposable to those of nodules with low suspicion of malignancy. The NIFT-P is almost never classified in the high-suspicious category according to the main US RSS. Therefore, although the preoperative identification of NIFT-P remains a challenge, neck US can be integrated in the algorithm of management of nodules with indeterminate cytology, suggesting a possible conservative approach in those with low-suspicious features.

Approach to the Patient With Parathyroid Carcinoma.

Parathyroid carcinoma (PC) is usually associated with severe symptomatic primary hyperparathyroidism (PHPT) and accounts for less than 1% of all cases of PHPT and approximately 0.005% of all cancers. PC most commonly occurs as a sporadic disease and somatic CDC73 mutations can be detected in up to 80% of cases. Approximately 30% of patients harbor a germline mutation of the CDC73 gene. Preoperative diagnosis of PC is difficult because no disease-specific markers are available, and PC should be suspected in patients with severe hypercalcemia and end-organ complications. The diagnosis is based on the evidence of invasive tumor growth at histology and/or metastases. En bloc resection of the tumor, together with the ipsilateral thyroid lobe and adjacent structures, should be performed by an experienced surgeon when PC is suspected. This surgical approach reduces the risk of recurrence and metastasis and offers the highest chance of cure. Nonetheless, PC has a recurrence rate of 40% to 60% and, if feasible, multiple surgical procedures should be performed. When surgery is no longer an option, medical treatment is aimed to reduce hypercalcemia and target organ complications. Targeted agents have been effectively used in a few cases. We describe herein a patient with severe PHPT due to PC and provide a systematic diagnostic and treatment approach. A thorough review of the medical history, a typical clinical and biochemical phenotype and, in some cases, the revision of the histological examination provide the clues for the diagnosis of PC.

Usefulness of second 131I treatment in biochemical persistent differentiated thyroid cancer patients.

Background: Second 131I treatment is commonly performed in clinical practice in patients with differentiated thyroid cancer and biochemical incomplete or indeterminate response (BiR/InR) after initial treatment. Objective: The objective of the is study is to evaluate the clinical impact of the second 131I treatment in BiR/InR patients and analyze the predictive factors for structural incomplete response (SiR). Patients and methods: One hundred fifty-three BiR/InR patients after initial treatment who received a second 131I treatment were included in the study. The clinical response in a short- and medium- long-term follow-up was evaluated. Results: After the second 131I treatment (median 8 months), 11.8% patients showed excellent response (ER), 17% SiR, while BiR/InR persisted in 71.2%. Less than half (38.5%) of SiR patients had radioiodine-avid metastases. Patients who, following the second 131I treatment, experienced SiR had larger tumor size and more frequently aggressive histology and vascular invasion than those experienced BiR/InR and ER. Also, the median values of thyroglobulin on levothyroxine therapy (LT4-Tg), Tg peak after recombinant human TSH stimulation (rhTSH-Tg) and thyroglobulin antibodies (TgAb) were significantly higher in patients who developed SiR. At last evaluation (median: 9.9 years), BiR/InR persisted in 57.5%, while 26.2% and 16.3% of the patients showed ER and SiR, respectively. About half of BiR/InR patients (71/153 (46.4%)) received further treatments after the second 131I treatment. Conclusions: Radioiodine-avid metastatic disease detected by the second 131I is an infrequent finding in patients with BiR/InR after initial treatment. However, specific pathologic and biochemical features allow to better identify those cases with higher probability of developing SiR, thus improving the clinical effectiveness of performing a second 131I treatment.

BRAF K601E Mutation in Oncocytic Carcinoma of the Thyroid: A Case Report and Literature Review.

BACKGROUND: Thyroid carcinoma (TC) is the most common endocrine cancer, with papillary thyroid carcinoma (PTC) being the most common subtype. BRAF and RAS oncogene were characterized as the most frequently altered genes in PTC, with a strong association between genotype and histotype. The most common mutation in BRAF gene is V600E and is prevalent in classic and aggressive variants of PTC, while BRAF K601E mutation is the most common among the other rare BRAF mutations. BRAF K601E mutated thyroid carcinomas are usually characterized by low aggressiveness, except for anecdotal cases of poorly differentiated TC. CASE PRESENTATION: We described a case of oncocytic carcinoma of the thyroid (OCA) with an aggressive clinical course, including widespread metastasis and resistance to radioiodine treatment. Molecular analysis revealed the exclusive presence of the BRAF K601E mutation in both primary tumor and metastatic lesions. Accordingly, a revision of the literature about aggressive TC cases carrying BRAF K601E mutation was performed. CONCLUSION: Although rare, this case emphasizes the relevance of considering BRAF K601E mutation in advanced non-PTC thyroid carcinomas, since it can be considered an actionable mutation for target therapies.

High Incidence of Thyroid Cancer in Southern Tuscany (Grosseto Province, Italy): Potential Role of Environmental Heavy Metal Pollution.

The incidence of thyroid cancer (TC) in Italy is one of the highest in Europe, and the reason for this is unclear. The intra-country heterogeneity of TC incidence suggests the possibility of an overdiagnosis phenomenon, although environmental factors cannot be excluded. The aim of our study is to evaluate the TC incidence trend in southern Tuscany, Italy, an area with particular geological characteristics, where the pollution and subsequent deterioration of various environmental matrices with potentially toxic elements (heavy metals) introduced from either geological or anthropogenic (human activities) sources are documented. The Tuscany cancer registry (ISPRO) provided us with the number of cases and EU standardized incidence rates (IR) of TC patients for all three provinces of southeast Tuscany (Siena, Grosseto, Arezzo) during the period of 2013-2016. In addition, we examined the histological records of 226 TC patients. We observed that the TC incidence rates for both sexes observed in Grosseto Province were significantly higher than those observed in the other two provinces. The increase was mostly due to the papillary (PTC) histotype (92% of cases), which presented aggressive variants in 37% of PTCs and tumor diameters more than 1 cm in 71.3% of cases. We demonstrated a high incidence of TC in Grosseto province, especially among male patients, that could be influenced by the presence of environmental heavy metal pollution.