Variant Of Follicular Carcinoma Research Articles

Lodine-131 uptake in a patient with cholelithiasis on post-therapeutic scan

A 71-year-old male patient was diagnosed with papillary carcinoma follicular variant after bilateral total thyroidectomy and radioactive iodine treatment was applied. The post-therapeutic whole-body scan demonstrated a focal 131I uptake in the right lobe of the liver in the right upper quadrant of the abdomen. Single-photon emission computed tomography/computed tomography (SPECT/CT) was performed to determine the precise localization of 131I uptake. It was understood that the identified focal 131I activity was due to cholelithiasis. In the same period, free-floating gallstones in the lumen and the gallbladder neck were observed on the abdominal ultrasonography

Dural and calvarial metastasis of thyroid follicular carcinoma mimicking Sindou type 6 parafalcine meningioma.

Fifty-two years, NID type-2 diabetic female was admitted with progressive headache, enlarging, pulsatile midline mass, dizziness, and numbness of extremities. Physical examination revealed only hypoesthesia in the upper left extremity C7-dermatome. Preoperative computed tomography revealed eroded parafalcian dural mass and caused a round 7 cm calvarial defect over the superior sagittal sinus (SSS) and another left parietal 1.2 cm satellite mass. Magnetic resonance imaging revealed an extra-axial, diffuse heterogeneous gadolinium-enhanced, well-circumscribed lesion invading the SSS and Trolard veins (bilaterally). Supratotal resection 1 cm from the tumor borders was performed, histopathology suggested papillary thyroid carcinoma follicular variant. The euthyroid patient underwent total thyroidectomy, and final pathology revealed invasive TFC. 5-year follow-up was uneventful without recurrence or new metastasis. Parafalcian meningioma classification was reviewed for the best surgical approach. The definitive diagnosis of meningioma should be established with histopathological analysis. TFC should be included in the differential diagnosis in cases of extra-axial tumors.

Alterations of regulatory factors and DNA methylation pattern in thyroid cancer.

DNA methylation plays an important role in thyroid oncogenesis. The aim of this study was to investigate the connection between global and local DNA methylation status and to establish the levels of important DNA methylation regulators (TET family and DNMT1) in thyroid tumours: follicular adenoma-FA, papillary thyroid carcinoma-PTC (classic papillary thyroid carcinoma-cPTC and papillary thyroid carcinoma follicular variant fvPTC). Global DNA methylation profile in thyroid tumours tissue (41 paired samples) was assessed by 5-methylcytosine and 5-hydroxymethylcytosine levels evaluation (ELISA), along with TETs and DNMT1 genes expression quantification. Also, it was investigated for the first time TET1 and TET2 promoter's methylation in thyroid tumours. BRAF V600E mutation and RET/PTC translocation testing were performed on all investigated samples. In vitro studies upon DNA methylation in K1 thyroid cancer cells were performed with demethylating agents (5-AzaC and vitamin C). TET1 and TET2 displayed a significantly reduced gene expression level in PTC, while DNMT1 gene presented a high level of expression. PTC samples presented increased levels of 5-methylcytosine and low levels of 5-hydroxymethylcytosine. 5-methylcytosine levels were associated with TET1/TET2 expression levels. TET1 gene expression was significantly lower in patients positive for BRAF mutation and with RET/PTC rearrangement. TET2 gene was found hypermethylated in thyroid carcinoma patients overall, especially in PTC-follicular variant samples (p= 0.0002), where TET2 gene expression levels were significantly reduced (p= 0.0031). Furthermore, the data indicate for all thyroid cancer patients a good sensitivity (81.08%) and specificity (86.49%) regarding the use of TET1 (p< 0.0001), and TET2 (71.79%, 64.10%, p= 0.0001) hypermethylation as biomarkers for thyroid oncogenesis. These results suggest that TET1/TET2 gene expression and methylation may serve as potential diagnostic tools for thyroid neoplasia. Our study showed that the methylation of TET1 increases in malignant thyroid tumours. fvPTC patients presented lower methylation levels compared to cPTC and could be a discriminatory factor between two cancer types and benign lesions. TET2 is a poorer discriminator between FA and fvPTC, but it can be useful for cPTC identification. K1-cells treated with demethylating agents showed a demethylation effect, especially upon TET2 gene. The cumulative effect of L-AA and 5-AzaC proved to have a potent combined demethylating effect on genes promoter's activation and could open new perspectives for thyroid cancer therapy.

SUN-LB81 Coexisting Malignant Struma Ovarii and Cervical Follicular Variant Papillary Thyroid Carcinoma

A 44-year-old woman presented with left lower quadrant abdominal pain for 2 months. Further evaluation revealed a left adnexal mass and she underwent a TAH-BSO. A 12 cm mass arising from the left ovary was resected which on microscopy appeared to be papillary thyroid carcinoma follicular variant arising from a mature teratoma (struma ovarii). A thyroid ultrasound showed two subcentimeter right thyroid nodules without any concerning lymphadenopathy. A total thyroidectomy was then performed to allow her to receive adjuvant RAI. The cervical thyroid pathology showed a 0.6 cm follicular variant papillary thyroid carcinoma with negative margins without angioinvasion, lymphatic invasion or extrathyroidal extension. Thyroid hormone suppression with levothyroxine was started. Preoperatively, thyroglobulin was 1381 ng/ml (nl range 1.3-31.8 ng/ml). After TAH-BSO and thyroidectomy, thyroglobulin was undetectable and so was the anti-thyroglobulin antibody. With an undetectable thyroglobulin level, it was decided not to pursue adjuvant RAI and continue TSH suppression with levothyroxine. Simultaneous existence of malignant struma ovarii and cervical papillary thyroid cancer is rare and has a favorable prognosis compared to metastasis to the ovaries from primary cervical thyroid papillary carcinoma. Due to the rarity of this condition, management is not clear or well supported by evidence. Various approaches are suggested by different authors, including thyroidectomy after resection of malignant struma ovarii to facilitate adjuvant RAI, only performing surgical resection of the ovarian tumor in the absence of high risk features or performing thyroidectomy and RAI only in metastatic or recurrent disease.

Case Report of a Clear-Cell Variant of Follicular Thyroid Carcinoma

Clear-cell variants of follicular carcinoma are rare subtypes of thyroid cancer. There is no unified view of the histopathological features of clear cell variants, but follicular carcinomas composed predominantly of clear cells are distinguished from clear cell variants. In clinical practice, it is important to determine whether clear cell variants arise primarily from the thyroid gland or are thyroid metastases of other clear cell carcinomas, such as renal cell carcinoma. We present a case in which a patient with initially suspected anaplastic thyroid carcinoma due to a rapidly progressive anterior neck mass was diagnosed with a clear cell variant of follicular carcinoma after a tissue biopsy. The patient was treated with lenvatinib, then his performance status improved, and he was discharged from the hospital. On day 188 after discharge, a contrast-enhanced computed tomography (CECT) scan of the neck showed further shrinkage of the tumor. However, a CECT scan of the chest revealed multiple lung metastases. On day 233 after discharge, the patient developed severe pneumonia resulting from tracheal rupture due to intratumoral necrosis. It was difficult to decide whether lenvatinib should have been discontinued or reduced when lung metastasis appeared. It is necessary to accumulate additional cases to make informed decisions about continuing lenvatinib therapy.

Pleomorphic giant cell anaplastic carcinoma arising in struma ovarii

Monodermal teratoma consist of predominantly (&gt;50%) or all component are thyroid tissue called struma ovarii. Malignant transformation of struma ovarii is very rare. Anaplastic carcinoma is the most rare type. A 52 years female with chief complaint of malaise and mass on lower abdomen. CT scan showed solid mass in ovarium that extend to upper abdominal cavity. CA-125 level is elevated. The frozen section was conducted, macroscopically showed tumor size is 15 cm, mostly composed of necrotic area, others are multicystic and solid area. Microscopic examination showed most are necrotic tissue with anaplastic cells in solid form, infiltrative between stromal with scattered pleomorphic giant cells. Benign struma ovarii component are found. The diagnosis was confirmed by examination of paraffin blocks from remain frozen section tissue, showed the same result. One area showed well differentiated carcinoma of papillary carcinoma follicular variant. Tumor was diagnosed as pleomorphic giant cell anaplastic carcinoma arising in struma ovarii based on clinical data, laboratory, radiological, macroscopic, and histopathology findings.Â

Follicular Variant of Papillary Carcinoma Arising in Struma Ovarii.

Sir, A 47-year-old female presented with pain in the right iliac fossa and excess menstrual bleeding since five months. Pain was non-radiating, gradual in onset and of moderate intensity. She was obese and anaemic. Abdominal examination revealed a single, soft to cystic, slightly mobile and non-tender mass in the right iliac fossa measuring 12x10cm. Examination of other systems were nil remarkable. Her haemoglobin was 11 gm/dl, TC, DC, Platelet count and urine examination was with in normal limits. Viral markers (VDRL, H.I.V and HBsAg) were nonreactive. Ultrasound abdomen revealed bulky anteverted uterus with fibroid in the anterior wall near the fundus and large right ovarian cyst. She was posted for total abdominal hysterectomy and right salpingoopherectomy. During surgery, there were no signs of capsular invasion or metastasis. Postoperative recovery is good. Gross examination revealed a 4cm size fibroid in the body of the uterus and right ovarian cyst of size 15x15x12cm. Cut section of right ovarian cyst showed grey brown solid area measuring 7x7x5cm and a unilocular cystic area filled with light brown colour fluid. Histopathology revealed follicular variant of papillary thyroid carcinoma arising from pre-existing struma ovarii of right ovarian cyst and interstitial leiomyoma of uterus [Table/Fig-1a-c] [Table/Fig-1a-d]: (a) Struma ovarii (HE (b-c) Thyroid type of papillary carcinoma (H&E, X100), (H&E, X400) - Microfollicles lined by cuboidal follicular ... To rule out occult teratocarcinomas, alpha-fetoprotein (2.02ng/ml) and alpha-1-antitrypsin (1.56g/dl) levels were estimated postoperatively, they were with in normal limits. Thyroid profile was within normal limits. To rule out occult primary, ultrasound neck and FNAC of thyroid was done and it revealed adenomatous goitre [Table/Fig-1d] Serum thyroglobulin levels were estimated after 6 months of the surgery they were within normal limits (2.8ng/ml). Struma ovarii is a monodermal variant of ovarian teratoma, which was composed of more than 50% of thyroid tissue. Malignant transformation of struma ovarii occurs rarely. Papillary and follicular thyroid carcinomas are the most frequent types of malignancy to occur in struma ovarii, whereas anaplastic and medullary carcinomas occur rarely [1]. A new variant of follicular carcinoma i.e. highly differentiated follicular carcinoma of ovarian origin (HDFCO) has been described by Roth and Karseladze which has an innocuous appearance, resembling that of nonneoplastic thyroid tissue in both the ovary and sites of dissemination [2]. Strumal carcinoid is a distinctive form of ovarian teratoma characterized by a mixture of thyroid tissue and carcinoid. Thyroid-type carcinoma can occur in strumal carcinoid [3]. Follicular variant of papillary thyroid carcinoma arising in struma ovarii exhibit diffuse positivity for CK19 and HBME-1(hector battifora mesothelial cell-1) which is similar to follicular variant of papillary carcinoma in cervical thyroid. Molecular analysis has revealed activating mutations of BRAF, NRAS, KRAS, RET/PTC and NTRK1 in approximately 70% of all follicular cell–derived thyroid carcinomas [1]. Surgical treatment includes total abdominal hysterectomy, plus bilateral salpingo-oophorectomy with omentectomy in postmenopausal women, or in premenopausal women who have completed childbearing [1]. Young women, with unilateral lesion without evidence of capsular invasion or gross metastasis, unilateral oophorectomy or strumectomy (cystectomy), should be performed for preservation of fertility [1]. Adjuvant therapy includes radioactive iodine ablation, external radiotherapy and chemotherapy. Radioactive iodine is the first-line therapy for treatment of recurrent disease [1]. Prognostic factors such as tumour size, extensive adhesions, capsular invasion, peritoneal dissemination, lymph nodal metastasis and solid histologic architecture were associated with an increased incidence of recurrence or metastasis. Anaplastic carcinoma is the most aggressive tumour type, followed by follicular, papillary and HDFCO is the least aggressive [4].

Invasion rather than nuclear features correlates with outcome in encapsulated follicular tumors: further evidence for the reclassification of the encapsulated papillary thyroid carcinoma follicular variant.

The prognosis of the encapsulated follicular variant of papillary thyroid carcinoma (EFVPTC) and its relationship to encapsulated follicular carcinoma (EFC) and follicular adenoma (FA) is subject to controversy. All EFVPTCs, EFCs, and FAs identified at a single institution between 1981 and 2003 were analyzed microscopically. A cohort of FAs from a different hospital was also examined. EFVPTCs were subdivided into noninvasive EFVPTC (NIEFVPTC) and invasive EFVPTC (IEFVPTC) displaying capsular/vascular invasion. There were 83 EFVPTCs (57 noninvasive, 26 invasive), 14 EFCs, and 52 FAs. Similar to FA, over a median follow-up of 9.5 years, none of the NIEFVPTCs manifested lymph node metastasis (LNM) or recurred. Furthermore, with a median follow-up of 10.5 years, none of 39 NIEFVPTCs without radioactive iodine therapy recurred. Four (15%) of 26 IEFVPTCs and none of 14 EFCs harbored distant metastasis (P = .29). There was no difference in LNM rate and degree of vascular or capsular invasion between IEFVPTC and EFC (P > .1). All 4 IEFVPTCs with adverse behavior presented with distant metastasis and no LNM. Sixteen percent of IEFVPTCs had poor outcome, whereas there was none in the NIEFVPTCs (P = .007). In conclusion, NIEFVPTC seems to behave similarly to FA, whereas IEFVPTC can metastasize and spread like EFC. Thus, invasion rather than nuclear features drives outcome in encapsulated follicular tumors. Non-IEFVPTC could be treated in a conservative manner sparing patients unnecessary total thyroidectomy and radioactive iodine therapy. The position of the EFVPTC in the classification of thyroid neoplasia should be reconsidered.

Thyroid Papillary Carcinoma Follicular Variant: Which Surgical Approach?

Thyroid Papillary Carcinoma Follicular Variant: Which Surgical Approach?

Incidental carcinoma of the thyroid

The diagnosis of incidental thyroid carcinoma in patients submitted to thyroidectomy for a benign disease is quite frequent. A retrospective analysis was performed on 455 patients submitted to surgical intervention in order to establish the incidence of this kind of carcinoma. Two hundred fifty-six patients (56%) were affected by benign disease (176 multinodular goiter, 12 uninodular goiter, 1 Plummer disease and 67 Basedow disease) and 202 (44%) by carcinoma. In 28 of 256 patients (11%), affected by benign disease, occurred a histological diagnosis of thyroid carcinoma, (10 papillary carcinoma, 1 follicular carcinoma, 29 papillary carcinoma follicular variant). In this study it's considered incidental thyroid carcinoma the one occurred in patients who never underwent Fine Needle Aspiration (FNA) and there were no suspicious features in all exams that may suggest the presence of carcinoma. Twenty-three of the 40 incidental carcinoma (57.5%) were microcarcinomas. Ten patients had a sincronous carcinoma. Actually, these patients are still in a follow up program and no recurrency of disease is occasionally observed. This study shows that the only way to put doubts on the real benignity of the disease is the fine needle aspiration; there are no other instruments that could identify the occurrence of the carcinoma. Moreover in the majority of cases the incidental carcinoma is a microcarcinoma, it doesn't reach significant volume, may be not centered by a FNA, but in most cases it’s not really biologically aggressive.

Immunohistochemical analysis of thyroid follicular neoplasms and BRAF mutation correlation.

The accurate diagnosis of benign and malign thyroid tumors is very important for the clinical management of patients. The distinction of thyroid papillary carcinoma follicular variant and follicular adenoma can be difficult. To investigate the alternative methods like immunohistochemistry and exon 15 in the BRAF gene 1799 T/A mutation analyses for distinguishing thyroid tumors. We applied immunohistochemical markers; CK19, HMWCK, Galectin-3, HBME-1 and Fibronectin and mutant allele-specific PCR amplification technique was used to determine 1799 T/A mutation within the BRAF gene. Formalin-fixed parafin embedded tissues from 45 surgically total resected thyroids, included 26 thyroid papillary carcinoma follicular variant (FV-TPC), 8 Follicular Adenoma (FA), 6 Minimal invasive follicular carcinoma (MIFC) and 5 Follicular Carcinoma (FC). Statistical Analyses Used: Pearson Chi-Square and Kruskal Wallis tests were performed. There was a positive correlation between FV-TPC and HMWCK, CK 19, HBME1, Galectin 3, fibronectin (P < 0.05), but there was no correlation with FV-TPC and BRAF gene mutation (P > 0.05). HBME-1 and CK 19 stained strong and diffuse positive in FV-TPCs but weak and focal in FAs. Our study suggests that morphologic features combined with immunohistochemical panel of HMWCK, CK19, HBME-1, Galectin-3 and fibronectin can help to distinguish benign and malign thyroid neoplasms and FV-TPC from follicular adenomas. BRAF gene 1799 T/A mutation has been non-specific but its detection can be a useful tool combined with immunohistochemistry for diagnosing FV-TPC.

Cutaneous metastasis as the presenting sign of papillary thyroid carcinoma

Cutaneous metastasis of visceral tumors accounts for 2% of skin tumors. We report the case of a 71-year-old male with a smoking history who presented to dermatology department with a violaceous nodule of the right sideburn skin. The lesion was interpreted as an adenocarcinoma that was completely excised and was suspicious for a metastasis. There was a recommendation for additional work-up. At a different institution, a positron emission tomography scan showed a left hilar mass and uptake in the right thyroid. He was then referred to our hospital for tissue diagnosis. Mediastinoscopy with biopsy of the left hilar mass showed metastatic follicular thyroid carcinoma. Subsequently, a thyroid fine needle aspirate showed suspicion for malignancy with similar morphology. Thyroidectomy and central neck dissection showed right thyroid papillary carcinoma extending to one margin and involving the lymph nodes. The left hilar metastasis mass resection showed similar lymph node findings. A re-review of the sideburn excision revealed similar histopathology to the thyroid and mediastinal resection. This case illustrates the opportunity of considering metastatic thyroid carcinoma to skin even in cases which lack the classic cytologic and architectural features of papillary thyroid carcinoma follicular variant.

Increasing Diagnosis of Thyroid Papillary Carcinoma Follicular Variant in South-East Anatolian Region: Comparison of Characteristics of Classical Papillary and Follicular Variant Thyroid Cancers

We aimed to compare ratios of thyroid cancers diagnosed in our regional reference hospital Pathology Center in Sanliurfa city located in southeast Anatolia, and evaluate the characteristics related with follicular variant papillary thyroid carcinoma (FVPTC). We re-evaluated the specimens of last 5 years thyroidectomies by same five pathologists, by same criteria and immunohistochemical evaluation. Chi-square test was used to compare characteristics of classical pure papillary thyroid carcinomas and FVPTC groups. Stepwise multiple regression analysis was used to evaluate the factors related with presence of FVPTC. Among 400 thyroidectomies, there were 105 papillary thyroid carcinoma, 42 of them with pure PTC, and 56 with FVPC, also seven with other variants. There was increase in ratios of FVPTC/PTC between 2010 and 2011 (68.4 vs 76.7%, p < 0.005). Radius, vascular invasion, and extrathyroidal invasion showed statistically significant difference between pure PTC and FVPTC. In regression analysis radius (p = 0.001, OR = 2.611; 95%CI, 2.010-3.391), age (p = 0.018, OR = 0.959; 95%CI, 0.927-0.993), and multicentricity (p = 0.044, OR = 0.403; 95%CI, 0.167-0.975) were related with presence of FVPTC. Besides, further need for studies to understand whether total prevalence of FVPTC is higher in this region, and the related factors, our study showed that the ratio of FVPTC/PTC is higher in our reference hospital. Age of the patients and the radius and multicentricity of the nodules could be alarming factors for us to suspect for FVPTC.

Role of Galectin-3 in Thyroid Cancer

Copyright: © 2012 Htwe TT. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Thyroid cancer (TC) is the most common endocrine malignancy with a rising incidence. It has a wide spectrum of clinical behavior and varied therapeutic responsiveness. Among the various forms of TC, papillary thyroid cancer (PTC) accounts for 85% of all TCs. It is the most common form compared to follicular carcinoma (FCA) and other rare forms such as medullary carcinoma (MCA), anaplastic carcinoma (ANA), poorly differentiated carcinoma (PDTC), undifferentiated thyroid carcinoma (UDTC), Hurthle cell carcinoma (HCA) and Insular carcinoma (Ins). In the past, PTC and FCA were generally identified by the difference in their clinical nature and the characteristic morphological features by using the conventional way of microscopy, following the guidelines from the World Health Organization (WHO). PTC is identified by its peculiar nuclear features and the papillary pattern whereas in FCA it is from its follicular pattern. The main criterion for the diagnosis of PTC is the occurrence of enlarged, round to oval shaped overlapping ground-glass nuclei, well known as OrphanAnnie eyes. The delicate papillary pattern of growth and the presences of laminated calcifications (psammoma bodies) are also diagnostic. For the FCA it is based on its closely packed follicular pattern and its tendency in invasiveness. However, there is a difficulty in identifying one sub type of TC known as papillary thyroid carcinoma follicular variant (PTCFC). Henceforth, with the development in immunohistochemical (IHC) techniques, experiments have been performed to find out novel molecular markers for TC, where Galectin-3 (Gal-3) has been identified as the most useful tumor marker among other galactosidebinding proteins such as Gal-1 and Gal-7.

Molecular genotyping of papillary thyroid carcinoma follicular variant according to its histological subtypes (encapsulated vs infiltrative) reveals distinct BRAF and RAS mutation patterns

Molecular genotyping of papillary thyroid carcinoma follicular variant according to its histological subtypes (encapsulated vs infiltrative) reveals distinct BRAF and RAS mutation patterns

Encapsulated Classic and Follicular Variants of Papillary Thyroid Carcinoma: Comparative Clinicopathologic Study

To compare the clinicopathologic features of papillary thyroid carcinoma classic variant (PTC-CV) and papillary thyroid carcinoma follicular variant (PTCFV), with a focus on the encapsulated form. In a retrospective search of computerized pathology files for 1996 to 1998, a cohort of 114 cases (58 cases of PTC-CV and 56 cases of PTC-FV) were selected for this study. Clinicopathologic data and long-term follow-up (serum thyroglobulin measurements, radiologic studies, and additional tissue sampling) through the date of compilation of study data were extracted from the medical records. The median patient age at initial diagnosis was 46 years for the PTC-CV group and 45.5 years for the PTC-FV group. Complete tumor encapsulation was seen in 40 PTC-CV cases (69%) and in all PTC-FV cases (100%). A higher rate of tumor capsule invasion (CI), lymphovascular invasion (LVI), extrathyroidal extension, and lymph node metastatic lesions was seen in PTC-CV than in PTC-FV: CI, 26% versus 18%; LVI, 17% versus 4%; extrathyroidal extension, 19% versus 7%; and lymph node metastatic lesions, 68% versus 29%. Clinical, radiologic, or pathologic follow-up data were available in 36 PTC-CV cases (62%) and 34 PTC-FV cases (61%). The median duration of follow-up for the PTC-CV group was 10 years and for the PTC-FV group was 9 years. Tumor recurrence was found in 10 patients with PTC-CV (28%) and 2 with PTC-FV (6%). Distant metastatic lesions occurred in 3 patients with PTC-CV (8%) and 1 patient with PTC-FV (3%) (P = .17); of these, 2 cases of PTC-CV were encapsulated and showed CI, LVI, and lymph node metastatic lesions. Our current study confirms previous reports that both encapsulated PTC-CV and encapsulated PTC-FV are indolent tumors and are associated with very low mortality.

Molecular genotyping of papillary thyroid carcinoma follicular variant according to its histological subtypes (encapsulated vs infiltrative) reveals distinct BRAF and RAS mutation patterns

The follicular variant of papillary thyroid carcinoma usually presents as an encapsulated tumor and less commonly as a partially/non-encapsulated infiltrative neoplasm. The encapsulated form rarely metastasizes to lymph node, whereas infiltrative tumor often harbors nodal metastases. The molecular profile of the follicular variant was shown to be close to the follicular adenoma/carcinoma group of tumors with a high RAS and very low BRAF mutation rates. A comprehensive survey of oncogenic mutations in the follicular variant of papillary thyroid carcinoma according to its encapsulated and infiltrative forms has not been performed. Paraffin tissue from 28 patients with encapsulated and 19 with infiltrative follicular variant were subjected to mass spectrometry genotyping encompassing the most significant oncogenes in thyroid carcinomas: 111 mutations in RET, BRAF, NRAS, HRAS, KRAS, PIK3CA, AKT1 and other related genes. There was no difference in age, gender, tumor size and angioinvasion between encapsulated or infiltrative tumors. Infiltrative carcinomas had a much higher frequency of extrathyroid extension, positive margins and nodal metastases than encapsulated tumors (P<0.05). The BRAF 1799T>A mutation was found in 5 of 19 (26%) of the infiltrative tumor and in none of the encapsulated carcinomas (P=0.007). In contrast, RAS mutations were observed in 10 of 28 (36%) of the encapsulated group (5 NRAS_Q61R, 3 HRAS_Q61, 1 HRAS_G13C and 1 KRAS_Q61R) and in only 2 of 19 (10%) of infiltrative tumors (P=0.09). One encapsulated carcinoma showed a PAX8/PPARγ rearrangement, whereas two infiltrative tumors harbored RET/PTC fusions. Encapsulated follicular variant of papillary thyroid carcinomas have a molecular profile very close to follicular adenomas/carcinomas (high rate of RAS and absence of BRAF mutations). Infiltrative follicular variant has an opposite molecular profile closer to classical papillary thyroid carcinoma than to follicular adenoma/carcinoma (BRAF>RAS mutations). The molecular profile of encapsulated and infiltrative follicular variant parallels their biological behavior (ie, metastatic nodal and invasive patterns).

QS263. Incidence of Follicular Thyroid Carcinoma: A 17 Year Experience of Pre-Operative Fine Needle Aspiration Classification As Follicular Lesion Versus Follicular Neoplasm

Background: Fine needle aspiration (FNA) classification of follicular thyroid nodules remains a challenging problem as the determination of benign from malignant disease is rarely possible. While research efforts search for Methods to pre-operatively classify follicular nodules that harbor malignancy, the decision for operative excision is largely based on clinical concerns, size of the nodule and age of the patient. We chose to re-examine our clinical outcomes based on the cytopathologic classification of follicular nodules at our institution. The purpose of this study was to assess the incidence of follicular carcinoma in thyroid nodules where the FNA diagnosis was follicular lesion versus follicular neoplasm and evaluate the utility of these diagnostic categories in triaging patients to sugery. We hypothesized that an interpretation of follicular neoplasm would carry a higher incidence of follicular carcinoma. Methods: We conducted a retrospective review of all patients with a diagnosis of follicular lesion or follicular neoplasm by FNA treated during the last 17 years at a single institution. Each record was independently reviewed. The diagnosis of follicular lesion was made on FNA when some colloid or variability in nuclei was suggestive of but not diagnostic for an adenomatous process. Follicular neoplasm was diagnosed on FNA when monotonous follicular cells with a paucity of colloid were present for which a follicular adenoma or carcinoma was favored. All cases with a suspicion for papillary thyroid carcinoma were excluded. All cases with a malignant diagnosis on the surgical resection specimen were evaluated for correlation with FNA site of biopsy and pathologic findings. Chi-squared analysis was used to determine significant differences in incidence of follicular carcinoma between follicular lesion and follicular neoplasm groups. A P- value less than 0.05 was considered significant. Results: Overall 614 patients with thyroid nodules underwent 672 FNAs: 518 were diagnosed as follicular lesion and 154 as follicular neoplasm. 356 (58.0%) patients underwent surgical resection composed of 239 (46.1%) of the patients with a preoperative diagnosis of follicular lesion and 117 (75.9%) of the patients with a cytopathologic diagnosis of follicular neoplasm. Follicular carcinoma was present in 16 (6.7%) of the follicular lesion group and 18 (15.4%) of the follicular neoplasm group. Overall, the incidence of malignancy including papillary thyroid carcinoma-follicular variant, papillary thyroid carcinoma and follicular carcinoma was 12.6% (30 of 239) for follicular lesions and 22.2% (26 of 117) for follicular neoplasms by FNA classification. The incidence of follicular carcinoma as well as overall malignancy was significantly higher for the follicular neoplasm group. Conclusions: At our institution, the cytopathologic evaluation by FNA of thyroid follicular nodules and their classification into follicular lesions versus follicular neoplasms serves to identify patients at greater risk for follicular carcinoma. Additionally, other malignancies are identified in a greater proportion of follicular neoplasms. Although malignancy may be present in either follicular neoplasms or follicular lesions, follicular neoplasms represent a higher risk nodule and thus this information is helpful when weighing the risk benefit ratio of surgical excision in a patient with a follicular nodule.

Mucinous variant of follicular carcinoma of the thyroid gland

Sir,We present a case of mucinous variant of minimally invasive follicular carcinoma of the thyroid gland. The production of mucin‐like substances by primary thyroid neoplasms1 has been increasingl...

Papillary thyroid cancer with an initial presentation of abdominal and flank pain

Purpose Well-differentiated thyroid cancer typically presents as a thyroid mass. Common sites of metastases upon presentation include cervical lymph nodes, lung, and bone. Well-differentiated thyroid cancer with clinically apparent kidney metastases is rare, with fewer than 20 cases reported in the literature. In the vast majority of these cases, the patients had known thyroid neoplasms at the time the renal metastases were identified. We report a case of papillary thyroid carcinoma that presented with abdominal pain in a 25-year-old woman with no previous history of thyroid disease. Study design This study is a case report. Results The patient underwent radical nephrectomy for a right renal mass, which was diagnosed as papillary thyroid carcinoma follicular variant. During subsequent evaluation, metastatic disease was also identified in the patient's lungs. The patient was treated with total thyroidectomy and iodine 131. Conclusions Papillary cancer, which ordinarily behaves in an indolent manner, can have unusual presentation, including disseminated metastasis on presentation. Renal metastases are extremely rare.