Medullary Thyroid Microcarcinoma Research Articles

Treatment and management of medullary thyroid microcarcinoma: a 10-year retrospective study from a single center.

To explore individualized treatment and management methods for medullary thyroid microcarcinoma (MTMC). Clinical data of patients with medullary thyroid carcinoma with a diameter ≤1 cm admitted to the First Affiliated Hospital of Kunming Medical University from June 2013 to June 20× were collected. Combined with different treatment guidelines for medullary thyroid carcinoma, factors affecting lymph node metastasis and postoperative disease status were analyzed. Twenty-nine patients with MTMC were included in the analysis, including 24 patients who underwent total thyroidectomy, 5 who underwent thyroid gland lobectomy, and 13 who experienced postoperative lymph node metastasis. Multifocal tumor and calcitonin (Ctn) were the influencing factors, while multifocal tumor, Ctn, lymph node metastasis, and AJCC stage affected the dynamic risk stratification of postoperative disease. Calcitonin detection is an important method for detecting MTMC. A tumor diameter ≤1 cm does not indicate that the tumor is in the early stage. The presence of multifocal tumors and Ctn should be used as important indicators for preoperative evaluation. Dynamic stratified risk assessment is critical in postoperative follow-up.

The pathological characteristics and prognostic analysis of medullary thyroid microcarcinoma

Objectives: To analyze the clinical characteristics and prognosis of medullary thyroid microcarcinoma (MTMC). Methods: A case series studies. The clinical data of patients with medullary thyroid carcinoma (MTC) diagnosed by postoperative pathology and with complete follow-up data who were initially treated in Tianjin Medical University Cancer Hospital from January 2013 to December 2019 were retrospectively analyzed. There were a total of 170 cases, including 70 males and 100 females, aged (49.7±12.3) years old. Among them, there were 61 patients with MTMC. They were divided into group A (with a maximum tumor idameter of ≤0.5 cm, n=13) and group B (with a maximum tumor diameter >0.5~≤1.0 cm, n=48) based on whether the maximum diameter of the tumor was >0.5 cm. Analysis was conducted on their pathological results and prognosis. Results: Among the MTC, MTMC accounted for 26.4% (61/231) with 26 males and 35 females aged M［Q1，Q3］51.0 (41.0, 59.0) years. Among the MTMC patients, 57.4% (35/61) were in stage Ⅰ, 16.4% (10/61) were in stage Ⅲ, and 26.2% (16/61) were in stage Ⅳ. For MTMC with a maximum diameter of≤0.5 cm and a maximum diameter of >0.5-≤1.0 cm, there was no statistically significant difference between the two groups in terms of gender, age, mixed cancer, invasion of glandular lobes, multifocal, central lymph node metastasis, lateral neck lymph node metastasis rate and other pathological characteristics(both P>0.05). In terms of prognosis, the recurrence free survival time of MTMC patients was 83.1 (68.0, 97.0) months. Among them, structural tumor recurrence occurred in 5 patients (8.2%) after surgery, and 1 patient (1.6%) died. The expected 5-year and 10-year survival rates were 93.4% and 89.0%, respectively. There was no statistically significant difference in recurrence free survival time among MTMC patients, MTC patients with a maximum diameter of >1.0-≤2.0 cm, and MTC patients with a maximum diameter of >2.0 cm (all P>0.05). Conclusion: MTMC has strong invasiveness, and although the prognosis of most MTMCs is relatively good, the risk of long-term recurrence and death is still high.

Medullary thyroid microcarcinoma revealed by lymph node metastases. about a case

Medullary thyroid microcarcinoma revealed by lymph node metastases. about a case

Diagnosis of medullary thyroid microcarcinoma by calcitonin measurement in fine-needle aspiration washout

Diagnosis of medullary thyroid microcarcinoma by calcitonin measurement in fine-needle aspiration washout

Clinicopathological characteristics and prognosis of medullary thyroid microcarcinoma: a tumor with a similar prognosis to macrocarcinoma

BackgroundTumor size plays an important role in the staging and treatment of thyroid carcinoma. A tumor with a maximum diameter of 1 cm or less is referred to as microcarcinoma. It is unclear if the clinicopathological characteristics and prognosis of medullary thyroid microcarcinoma (≤ 1 cm; MTMC) and macrocarcinoma (> 1 cm) differ. The present study aims to clarify the clinical features and prognosis of patients with MTMC.MethodsThe patients with medullary thyroid carcinoma underwent radical operation at our hospital between December 2000 and January 2022 were retrospectively studied. A database was established for this study. Patients with MTMC and macrocarcinoma were grouped for comparison. The clinicopathological characteristics of the two groups were compared by χ2 test, Fisher’s exact test, t-test, and Mann–Whitney U test. Cumulative survival rates were presented by the Kaplan–Meier curves and compared using the log-rank test.ResultsA total of 198 patients were included. Of them, 56 and 142 with MTMC and macrocarcinoma, respectively. Few patients in the MTMC group had lateral lymph node metastasis. One hundred and seventy-eight (89.9%) patients were followed up, with a median follow-up period of 61 (35, 105) months. The disease-free survival rate was significantly higher in the MTMC group (log-rank test, p = 0.032); however, there was no significant difference in the overall survival rate between the two groups (log-rank test, p = 0.083).ConclusionsPatients with MTMC have a lower risk of lateral lymph node metastasis and better disease-free survival than those with macrocarcinoma. However, there was no significant difference in the overall survival rate of both groups. MTMC should be treated in the same manner as macrocarcinoma.

Prognostic Factors and Long-Term Outcomes of Medullary Thyroid Microcarcinoma in a Retrospective Cohort Study

Prognostic Factors and Long-Term Outcomes of Medullary Thyroid Microcarcinoma in a Retrospective Cohort Study

Natural History and Predictive Factors of Outcome in Medullary Thyroid Microcarcinoma.

Management of sporadic medullary thyroid microcarcinoma smaller than 1 cm (micro-MTC) is controversial because of conflicting reports of prognosis. As these cancers are often diagnosed incidentally, they pose a management challenge when deciding on further treatment and follow-up. We report the outcomes of surgically managed sporadic micro-MTC in a specialist endocrine surgery and endocrinology unit and identify associations for recurrence and disease-specific survival in this population. Micro-MTCs were identified from a prospectively maintained surgery database, and slides were reviewed to determine pathological grade. The primary end points were recurrence, time to recurrence and disease-specific survival. Prognostic factors assessed included size, grade, lymph node metastasis (LNM), and postoperative calcitonin. From 1995 to 2022, 64 patients were diagnosed with micro-MTC with 22 excluded because of hereditary disease. The included patients had a median age of 60 years, tumor size of 4 mm, and 28 (67%) were female. The diagnosis was incidental in 36 (86%) with 4 (10%) being high grade, 5 (12%) having LNM and 9 (21%) having elevated postoperative calcitonin. Over a 6.6-year median follow-up, 5 (12%) developed recurrence and 3 (7%) died of MTC. High grade and LNM were associated with 10-year survival estimates of 75% vs 100% for low grade and no LNM (hazard ratio = 831; P < .01). High grade, LNM, and increased calcitonin were associated with recurrence (P < .01). Tumor size and type of surgery were not statistically significantly associated with recurrence or survival. No patients with low grade micro-MTC and normal postoperative calcitonin developed recurrence. Most sporadic micro-MTCs are detected incidentally and are generally associated with good outcomes. Size is not significantly associated with outcomes. Using grade, LNM, and postoperative calcitonin allows for the identification of patients at risk of recurrence to personalize management.

Mediastinal Mass as First Clinical Manifestation of Medullary Thyroid Microcarcinoma in a Patient With Hashimoto’s Thyroiditis

Medullary thyroid cancer is a rare neuroendocrine tumor with aggressive behavior and an uncertain prognosis. Calcitonin is the associated tumor marker; however, neuroendocrine tumors of the lung or intestine can also present high values. We report the case of a 53-year-old patient presenting with dry cough for 3 years. Computed tomography (CT) showed a 58-mm expansive lesion in the right anterior mediastinum and cervical ultrasound informed a 9-mm hypoechoic nodule with a lobulated edge and thick calcifications. Cytology reported Hashimoto’s thyroiditis. He underwent emergent surgery for respiratory failure. The pathological study informed G2 neuroendocrine carcinoma, immunohistochemistry showed: cytokeratin (+), vimentin (+), alpha-actin (-), synaptophysin (+), chromogranin (+), Ki-67: 10%. He progressed with bone metastasis visualized in scintigraphy and mediastinal tumor remnants, adenopathy, and pulmonary nodules on CT scan, prompting chemotherapy. Due to elevated and increasing calcitonin, an ultrasound study with needle washout for calcitonin resulted in 1,724 pg/mL, and cytology of the nodule reported medullary carcinoma. He was finally diagnosed with medullary thyroid microcarcinoma with metastasis to the mediastinum. Coexistence with Hashimoto’s thyroiditis could alter the initial fine-needle aspiration results. We conclude that in the case of calcitonin-secreting neuroendocrine tumors or medullary thyroid cancer, calcitonin fine needle aspirate washout may be helpful in elucidating a diagnosis. Due to its severity, medullary thyroid cancer should always be approached and managed aggressively, even microcarcinomas. J Endocrinol Metab. 2022;12(6):198-201 doi: https://doi.org/10.14740/jem841

RF07 | PSUN366 An Uncommon Path Leading to Diagnosis of Multiple Endocrine Neoplasia 2A

Abstract Introduction MEN2 is a rare Autosomal Dominant disorder resulting from mutations in the RET proto-oncogene. MEN2 is classified into two distinct syndromes: MEN2A and MEN2B. MEN2A is a syndrome that presents with Medullary Thyroid Carcinoma (MTC) in 90% of adult gene carriers, unilateral or bilateral pheochormocytoma in 50%, and multigland parathyroid tumors in 20-30% of affected individuals. Other rare variants of MEN2 include Familial Medullary Thyroid Carcinoma (FMTC), MEN2A with cutaneous lichen amyloidosis, and MEN2A or FMTC with Hirschprung's disease. We present a patient with incidentally noted elevated calcitonin levels, later diagnosed with MEN2A. Clinical Case 37-year-old Caucasian male was referred to our clinic for elevated calcitonin levels noted on lab work done as part of evaluation and management for weight loss prior to initiating GLP-1 agonists. He was diagnosed with hypothyroidism and multinodular goiter and started on Synthroid. His only symptoms were weight gain, tiredness, soft stools and facial flushing He denied any family history of endocrine disorders. Physical exam was unremarkable. Pertinent labs included serum calcitonin 93 pg/mL (&amp;lt;10 pg/mL), serum CEAg 5.2 ng/mL (0-3 ng/mL), and work up for pheochromocytoma and hyperparathyroidism was negative. USG thyroid showed a left lobe thyroid nodule measuring 7×5×7 mm with macrocalcifications, a right lobe thyroid nodule measuring 8×5×10mm, and an abnormal left lateral level III LN. He underwent left thyroid lobectomy with level VI neck dissection (total thyroidectomy aborted due to hypoxia), and subsequently completion thyroidectomy with right central neck dissection. Pathology showed metastatic MTC with pathologic staging pT1aN1a. Genetic testing showed RET c. 1826G&amp;gt;A (p. C609Y) which is ATA – MOD risk. Patients’ father was also genetically screened and diagnosed with MEN2A and noted to have elevated calcitonin levels. He also subsequently underwent total thyroidectomy, which revealed medullary thyroid microcarcinoma. Conclusion A number of studies support that measurement of serum calcitonin is the most sensitive screening test for detecting occult MTC in individuals with thyroid nodules. Yet, the use of serum calcitonin in the routine evaluation of thyroid nodules is controversial due to absence of uniform calcitonin thresholds, high false positive values and unavailability of pentagastrin stimulation testing. Moreover, there are no recommendations based on the current data to check calcitonin levels prior to initiating GLP-1 agonists but their use is not recommended in patients with personal or family history of MTC/MEN2. Based on the above case, measurement of calcitonin levels should be a part of the work up in patients who present with thyroid nodules and are receiving GLP-1 agonists. Attention should also be paid to the importance of genetic counseling in first-degree relatives of patients with MEN2A. This allows for timely diagnosis and reduces morbidity and mortality. Presentation: Saturday, June 11, 2022 1:30 p.m. - 1:35 p.m., Sunday, June 12, 2022 12:30 p.m. - 2:30 p.m.

Paediatric thyroidectomy: When and why? A 25-year institutional experience

ObjectiveThyroidectomy in paediatric patients is relatively uncommon. In this study, we reviewed our experience of thyroidectomy in children and identified risk factors associated with postoperative complications. MethodsWe performed a retrospective analysis of paediatric patients who had thyroidectomy in our institution between April 1995 and January 2021. Demographic data, preoperative cytological findings, indications of surgery, surgical complications and histological results were analysed. ResultsA total of 87 paediatric patients with 92 thyroidectomy were identified. The indications for surgery were Graves’ disease refractory to medical treatments (40.2%), benign thyroid nodules or multinodular goitre (26.4%), thyroid carcinoma (23.0%) and multiple endocrine neoplasm type 2A syndrome (10.3%). Patients presented with thyroid nodules or cervical lymph nodes had a 43.9% risk of malignancy.66 total thyroidectomy were done with median operation time of 134 min(102–170), while 26 hemi-thyroidectomy were performed (Right side 12/92, Left side 14/92) with median operation time of 65 min(49–102). The median postoperative hospital stay was 2 days(1–4). Intraoperative neck dissection (p = 0.003), drain insertion (p = 0.001) and hypocalcaemia requiring medical treatment (p = 0.004) were associated with longer hospital stay.The median follow-up was 11.3 years (3.0–16.8). 32% patients had immediate postoperative hypocalcaemia and 8% patients had permanent hypoparathyroidism. Transient vocal cord palsy was found in 3 patients(3%) and all resolved within 5-month time upon reassessment direct laryngoscopy. The use of intraoperative recurrent laryngeal nerve monitoring was associated with less vocal cord palsy (p = 0.022).The median disease-free survival was 13.7 years(7.4–17.7) for patients operated for well-differentiated thyroid carcinoma(WDTC). amongst the 9 patients who had prophylactic total thyroidectomy for MEN2A syndrome, 44% were found to have medullary thyroid microcarcinomas on pathology. ConclusionsSurgical management of paediatric thyroid disease can be complex. Postoperative hypocalcaemia and vocal cord palsy were usually transient after total thyroidectomy. The use of intraoperative recurrent laryngeal nerve monitoring had resulted in less vocal cord palsy. Long-term disease-free survival of patients with thyroid cancer had been achieved with multi-disciplinary management in our centre.Level of Evidence: Retrospective Comparative Study; Level III

Predictive factors for lymph node involvement in sporadic medullary thyroid microcarcinoma: a systematic review.

The aim of the study was to determine the impact of laboratory and imaging tests in predicting central and lateral neck lymph node/LN involvement and in decision making for surgical extent. A PubMed, Web of Science and Scopus search was performed according to PRISMA criteria. The relationship between nodule size, diagnostic biomarkers and imaging with LN involvement were evaluated. The available data analysis did not yield clear indications of the relationship between each of these topics and the presence, number, and location of LN involved. There was no conclusive data for the selective indication of central neck dissection in the preoperative diagnosis of microMTC. There is no justification for less invasive interventions than total thyroidectomy with lymph node dissection.

Solid Cell Nests Hyperplasia (Ultimobranchial Body Remnants) of the Thyroid: A Pitfall

Abstract Introduction/Objective Solid cell nests (SCN) are small epithelial cell nests interspersed within thyroid parenchyma, resembling squamous/transitional epithelium. SCNs, which are ultimobranchial remnants, are popularly considered pluripotent stem-cells responsible for developing follicular and C-cells. While SCNs are not an uncommon incidental findings in thyroid, solid cell nest hyperplasia is rare. SCNs are often mistaken for benign entities such as C-cell hyperplasia (CCH) or malignant lesions such as papillary thyroid carcinoma (PTC), metastatic squamous cell carcinoma, or medullary thyroid microcarcinoma (MTC). Methods/Case Report To reiterate this diagnostic dilemma, we present a case of a 57-year-old male with a six-year history of Hashimoto thyroiditis and multiple bilateral thyroid nodules. Ultrasonography revealed two nodules, one in each lobe, measuring 2.0x1.9x1.8cm(right) and 1.6x1.5x1.5cm(left). Both were solid, hypoechoic nodules with smooth margins and no echogenic foci. Fine-needle aspiration of right nodule was suspicious for follicular neoplasm, Hürthle- cell type, and the left nodule was atypia of unknown significance. Right-hemithyroidectomy specimen revealed follicular adenoma and oncocytic adenomatous nodules in a background of florid lymphocytic thyroiditis (Hashimoto). In two blocks, small solid nests of cells were identified, largest focus measuring 0.5 cm. The cells were polygonal to epithelioid with moderate amphophilic cytoplasm. Nuclei were centrally located, irregular to oval with occasional grooves. While nests had a squamoid appearance, they did not have intercellular bridges. Although nuclear grooves and evenly dispersed chromatin and chromocenters were noted, they lacked optical clearing or intra-nuclear inclusions characteristic for PTC. Thus, excluding these two possibilities, primary diagnostic considerations were SCN versus CCH. Immunohistochemical analysis showed cells positive for P63 and CK5/6 and negative for PAX-8, TTF-1, thyroglobulin, CEA, and calcitonin. Results (if a Case Study enter NA) NA Conclusion If wrongly diagnosed as CCH, patients may be placed in a high-risk category for possible development of MTC. It is, thus, necessary to be aware of SCN, which can occasionally become hyperplastic, to prevent misdiagnosis.

FOLLICULAR VARIANT OF PAPILLARY THYROID CARCINOMA AND MEDULLARY THYROID MICROCARCINOMA OCCURRING SIMULTANEOUSLY IN THE THYROID: A RARE CASE

<h3>Background</h3> Follicular variant of papillary thyroid carcinoma (FV-PTC) is a variant that develops from follicular cells, showing the nuclear properties of papillary thyroid carcinoma. Medullary thyroid carcinoma (MTC) is a malignant neuroendocrine tumor that develops from parafollicular C cells. It is more common in the fifth to sixth decades and in women. MTC smaller than 10 mm is referred to as medullary thyroid microcarcinoma (microMTC). <h3>Case</h3> A 59-year-old female patient with follow-up due to multinodular goiter underwent total thyroidectomy. Macroscopically, a 3.6 × 2 cm encapsulated solid nodular lesion in the right lobe and smaller nodular lesions in all thyroid material were observed. Microscopically, a tumor with capsular invasion had a follicular pattern of cells containing nuclear enlargement, nuclear crowding, nuclear overlapping, nuclear clearing, and nuclear groove on the background of multinodular goiter in the right lobe. In a separate focus at a distance of 1 mm from the tumor, a 5-mm infiltrative lesion of cell groups with eosinophilic sitoplasma containing polygonal, oval and elongated hyperchromatic nucleus with nucleoli in a stromal amyloid material was observed. Immunohistochemically, there was focal positive CK19 and luminal positive HBME-1 staining in the first lesion. Galectin-3 was negative. In the second lesion, positive calcitonin and CEA staining were striking. The first lesion as FV-PTC and the second lesion as microMTC were reported. <h3>Conclusions</h3> It is very rare to see synchronized occurrence of FV-PTC and microMTC originating from different cells as 2 different primers in the same thyroid lobe. Whether the occurrence is coincidental or by common mutation remains a mystery today.

Cytology versus calcitonin assay in fine-needle aspiration biopsy wash-out fluid (FNAB-CT) in diagnosis of medullary thyroid microcarcinoma.

Widespread use of sensitive ultrasound examination led to an increasing detection of medullary thyroid microcarcinoma (micro-MTC). This prospective study evaluated the diagnostic accuracy of Fine-needle Aspiration Biopsy Cytology (FNAB-C) and calcitonin assay in Fine-needle Aspiration Biopsy wash-out fluid (FNAB-CT) in thyroid nodules less than 1 cm with elevated serum calcitonin(sCT). 87 thyroid nodules from 60 patients with elevated sCT (>10 pg/ml) were included and 51 were thyroid nodules less than 1cm. FNAB-CT and FNAB-C were performed to distinguish medullary thyroid carcinoma (MTC) lesions before surgery, histopathologic diagnoses served as main reference standards. FNAB-CT had a greater performance over FNAB-C for preoperative diagnosis of MTC (diagnostic accuracy: 98.85 vs 61.90%, sensitivity: 98.55 vs 55.07%, specificity: 100 vs 97.44%), especially for micro-MTC: FNAB-C established a sensitivity and diagnostic accuracy of 48.78 and 58% respectively, while FNAB-CT reached 97.56% sensitivity and 98.04% diagnostic accuracy. FNAB-CT demonstrated high diagnostic accuracy in diagnosing micro-MTC. Patients with microscopic thyroid nodules and elevated sCT level should perform FNAB-CT to exclude the diagnosis of MTC lesions.

Genomics and Epigenomics of Medullary Thyroid Carcinoma: From Sporadic Disease to Familial Manifestations.

Our understanding of the genomics and epigenomics of medullary thyroid carcinoma (MTC) has advanced since the initial recognition of RET as a driver of MTC tumorigenesis in familial MTC. We now have insight into the frequency and prognostic significance of specific RET mutations in sporadic MTC. For example, the most common RET mutation in sporadic MTC is the RET Met918Thr mutation, the same mutation that underlies MEN2B and a poor prognosticator. This mutation is relatively infrequent in medullary thyroidmicrocarcinomas but is over-represented in advanced-stage disease. RAS mutations are detected in 70% of sporadic, RET wild-type MTC. Although next-generation and whole-exome sequencing studies have shown that tumors that are wild-type for RET and RAS mutations essentially lack other recurrent mutations, additional pathways and epigenetic alterations have been implicated in MTC tumorigenesis. Increased insight into the clinical course of patients with familial MTC with specific RET mutations has guided treatment recommendations for these patients. Finally, an understanding of the genomics has informed treatment for patients with advanced MTC. In this review, we will examine the genomics and epigenomics of sporadic and familial MTC, along with the prognostic significance of molecular alterations, management of patients with germline RET mutations, and treatment strategies for MTC patients.

Clinical and ultrasonographic features of medullary thyroid microcarcinomas compared with papillary thyroid microcarcinomas: a retrospective analysis

BackgroundTo identify the sonographic features that help to differentiate medullary thyroid microcarcinomas (MTMCs) from papillary thyroid microcarcinomas (PTMCs).MethodsA total of 46 MTMCs in 41 patients and 136 PTMCs in 104 patients that were proven by surgery and pathology were included in the study. Patient age and nodule size were analyzed by independent sample t-tests, and sex, multiplicity and cervical lymph node metastases were analyzed by χ2 or Fisher’s exact tests. Univariate analysis and multivariate logistic regression analysis were performed on the sonographic features of thyroid nodules, including location, shape, boundary, margin, peripheral halo ring, echogenicity, composition, calcifications and vascularization.ResultsCompared with the corresponding number of patients with PTMCs, more MTMC patients had cervical lymph node metastases (P = 0.040). There were no significant differences in age, sex, nodule size, multiplicity, location, boundary, margin, peripheral halo ring, echogenicity or microcalcifications between MTMCs and PTMCs (P > 0.05 for all). However, significant differences were found in shape (P = 0.000), composition (P = 0.032), macrocalcifications (P = 0.004) and vascularity (P = 0.000) between the two groups.ConclusionsThere were some overlapping sonographic features between MTMCs and PTMCs. However, MTMCs tended to have a > 50% solid composition, be ovoid to round nodules with macrocalcifications and be hypervascular. Cervical lymph node metastases were more common in MTMC patients.

Usefulness of Serum Calcitonin in Patients with Thyroid Nodules ≤ 1 cm Without an Indication for Fine-Needle Aspiration.

Fine-needle aspiration (FNA) is not necessary in adults with nodules ≤ 1 cm without apparent extrathyroidal extension (ETE) or lymph node (LN) involvement on ultrasonography (US). In the absence of FNA and serum calcitonin (Ctn) measurement, medullary thyroid microcarcinomas (microMTC) are not diagnosed. The aim of this prospective study was to evaluate Ctn levels in adults with a low clinical risk of MTC and nodules ≤ 1 cm without ETE or LN involvement on US. A total of 506 consecutively seen adults who had nodules with two or more suspicious features were included. Patients with elevated basal Ctn underwent a calcium stimulation test and FNA. Basal Ctn was normal in 490 patients (96.8%). In the 16 patients with elevated basal Ctn, FNA revealed MTC in only one patient and MTC was not suspected in the 15 patients with elevated basal Ctn. Three patients with stimulated Ctn<100 pg/ml and benign cytology were not submitted to surgery. MTC was excluded by histology in three patients with stimulated Ctn<100 pg/ml and indeterminate or suspicious cytology and in eight patients with stimulated Ctn>100 pg/ml. One patient with stimulated Ctn>100 pg/ml had MTC. Ctn was undetectable 6 months after surgery in two patients with MTC. Although uncommon, even subjects without a suspicious history and with nodules ≤ 1 cm without ETE or LN involvement on US, but with suspicious findings, can have microMTC. The measurement of Ctn permits the diagnosis of these cases.

Intraoperative lymphonodal staging of clinically N0 medullary thyroid microcarcinomas for decision on lateral neck dissection

Background: Serum calcitonin (Ct) levels in medullary thyroid carcinoma (MTC) usually correlate with tumor size and disease extent. Majority of surgeons recommend total thyroidectomy (TT) and central neck dissection (CND) in proven or suspected MTC, but the extent of lateral neck dissection (LND) remains controversial. The aim of this study was to analyze usefulness of sentinel lymph node (SLN) biopsy with methylene blue dye (MBD) for intraoperative lymph node (LN) staging and selection of clinically N0 (cN0) patients with micro-MTCs and serum Ct level below 1000pg/ml for one-time LND, along with TT and CND.

Abstract #604 Mediastinal Mass as the First Manifestation of a Medullary Thyroid Microcarcinoma

Abstract #604 Mediastinal Mass as the First Manifestation of a Medullary Thyroid Microcarcinoma

Sentinel lymph node biopsy of jugulo-carotid regions in medullary thyroid microcarcinomas after methylene blue dye mapping – a single institution experience

Sentinel lymph node biopsy of jugulo-carotid regions in medullary thyroid microcarcinomas after methylene blue dye mapping – a single institution experience