Yasuhiro Ito

• Kuma Hospital

The Japan Association of Endocrine Surgery published the first edition of the “Clinical guidelines on the management of thyroid tumors” in 2010 and the revised edition in 2018. The guideline presented herein is the English translation of the revised third edition, issued in 2024. The aim is to enhance health outcomes for patients suffering from thy...

The latest “General Rules for the Description of Thyroid Cancer,” published in 2023, introduced depth-based subcategories of tumor invasion, dividing sEx2 into sEx2a, sEx2b, and sEx3. However, the “Clinical Guidelines on the Management of Thyroid Tumors,” published in 2024, continue to classify these categories uniformly as high-risk for papillary...

Managing thyroid nodules diagnosed cytologically as follicular neoplasms (FN) is challenging for patients and clinicians. Gene panel testing was recently introduced to determine the management strategy for FN; however, it is unavailable in Japan. In this study, we assessed FN management. This study included 2,144 FNs from 2,067 patients diagnosed b...

Background Papillary thyroid carcinoma (PTC) occasionally invades the trachea and requires airway resection. Tracheal excision site recurrence (ESR) is a serious problem. We investigated predictors of ESR in patients with PTC who underwent airway resection for locally curative surgery. Methods We enrolled 149 patients with PTC who underwent airway...

Background Patients with intermediate‐risk papillary thyroid carcinoma (PTC) have a favorable prognosis with standard treatment of total thyroidectomy (TT) and adjuvant radioactive iodine therapy (RAIT). However, the benefits of TT or adjuvant RAIT remain undetermined, and they are often omitted in Japan. We investigated risk factors for life‐threa...

Background Papillary thyroid carcinoma (PTC) often extends to adjacent organs. According to the 8th Tumor‐Node‐Metastasis Classification, extension to the strap muscles was graded as T3b. We investigated the prognostic impact of T3b and the appropriateness of T3b in patients aged ≥55 years who were classified as stage II. Methods We enrolled 7811...

Objectives Injury to the external branch of the superior laryngeal nerve (EBSLN) causes low‐pitch voice and voice fatigue, particularly in female subjects, and available treatments are limited. Here, we assess a novel surgical procedure to restore a high‐tone voice: ansa cervicalis to EBSLN anastomosis (A‐E anastomosis). Methods Between November 2...

Active surveillance (AS) for low-risk (T1aN0M0) papillary microcarcinoma of the thyroid (PTMC) was initiated at Kuma Hospital (Kobe, Japan) in 1993 and is now being adopted worldwide. To date, favorable outcomes of patients under AS have been reported in Japan, Korea, the United States, and Italy etc. In this chapter, we describe the indications an...

The use of active surveillance (AS) of low-risk papillary microcarcinoma of the thyroid (T1aN0M0, PMC) was initiated at Kuma Hospital (Kobe, Japan) in 1993 and is now spreading worldwide. Favorable outcomes of patients with PMCs have been reported in both Japan and other countries. In this chapter, we describe the indications, implementation approa...

Active surveillance (AS) for low-risk papillary thyroid microcarcinoma (PTMC), which was initiated at Kuma Hospital (Kobe, Japan) in 1993 and Cancer Institute Hospital (Tokyo) in 1995, is now gradually being adopted worldwide, and several prospective studies have described the favorable outcomes of PTMC patients who underwent AS. The most important...

The thyroid gland's neurovascular relationship is commonly portrayed as the recurrent laryngeal nerve (RLN) coursing posteriorly to the thyroid gland. We report a rare case with the RLN running anteriorly to a thyroid tumor. A 56-year-old Japanese woman underwent a thyroidectomy for a benign thyroid tumor. Preoperatively, computed tomography confir...

Active surveillance (AS) is an accepted management option for patients with low-risk papillary thyroid microcarcinoma (PTMC), although some patients undergo immediate surgery (IS). At surgery, patients may have risky features such as adhesion or invasion to the adjacent organs. The surgical outcomes of this subset of patients are unknown. Here, we...

Background: During active surveillance (AS), serum thyroid-stimulating hormone (TSH) levels may affect papillary thyroid microcarcinoma (PTMC) progression. We investigated AS outcomes according to whether levothyroxine (LT4) treatment was administered. Patients and methods: From 2005 to 2019, 2,896 patients with low-risk PTMC underwent AS. Of th...

Active surveillance for low-risk papillary thyroid microcarcinoma (PTMC; T1aN0MI) was initiated at Kuma Hospital, Kobe, Japan, in 1993, based on a proposal by Akira Miyauchi. Favorable outcomes of such surveillance have been reported. Our latest study revealed 5- and 10-year tumor enlargement rates (by ≥3 mm) at 3.0% and 5.5% and 5- and 10-year nod...

Background: It has been 30 years since the initiation of active surveillance (AS) for adult patients with low-risk papillary thyroid microcarcinoma (PTMC). This study compared the long-term oncological outcomes of patients who underwent AS or immediate surgery (IS). Methods: This is a retrospective review of extended follow-up data from patients...

Although the outcomes of active surveillance (AS) for low-risk papillary thyroid microcarcinoma (PTMC) are generally excellent, some patients undergo conversion surgery for various reasons, including disease progression. We studied the outcomes of PTMC patients who underwent AS, who underwent conversion surgery after AS, and who underwent immediate...

Background: Active surveillance (AS) for low-risk papillary thyroid microcarcinoma (PTMC) was initiated at Kuma Hospital in 1993 and has gradually spread worldwide. We previously demonstrated that AS is associated with a much lower incidence of unfavorable events than immediate surgery (IS). However, conversion surgery (CS) raises concerns about i...

Background Active surveillance (AS) of low-risk papillary thyroid microcarcinoma (PTMC) was initiated at Kuma Hospital in 1993 and is gradually spreading worldwide. We assessed the effect of thyroid-stimulating hormone (TSH) levels on PTMC enlargement in patients on AS. Methods We enrolled 2705 patients with cytologically diagnosed PTMC who had un...

Intrathyroidal thymic carcinoma (ITTC) is a rare malignancy of the thyroid. It is thought to originate from ectopic thymic tissue or embryonic thymic rest, in, or adjacent to, the thyroid. We analyzed the backgrounds, clinicopathological features, and prognosis of 20 patients with ITTC, treated at our hospital. Thirteen of the 15 patients (86%) who...

The World Health Organization (WHO) classifies follicular thyroid carcinoma (FTC) into three categories: minimally invasive (mFTC), encapsulated angioinvasive (eaFTC), and widely invasive (wFTC). This study investigated whether this classification is appropriate. We enrolled 523 patients who underwent initial surgery at Kuma Hospital between 1998 a...

Older age is recognized as a predictor of poor prognosis in papillary thyroid carcinoma (PTC) patients. However, young age is associated with disease progression of PTC measuring 1 cm or smaller in patients on active surveillance. In this study, we investigated the relationship between patient age and prognosis of PTC belonging to very low-, low-,...

Background The major sites of distant metastases of papillary thyroid carcinoma (PTC) are the lung and bone; metastasis to the liver is rare. Although the postoperative serum thyroglobulin (Tg) level after total thyroidectomy is a good prognostic indicator for PTC when anti-thyroglobulin antibody (TgAb) is negative, the presence of TgAb interferes...

Thyroid tumors arising from follicular cells can generally be divided into malignant and benign tumors. However, some cases are difficult to clearly diagnose whether they are benign or malignant. Therefore, in the most recent version of World Health Organization (WHO) classification, some borderline lesions such as follicular tumor of uncertain mal...

Vocal cord paralysis (VCP) induced by resection of the recurrent laryngeal nerve (RLN) due to carcinoma invasion or an accident compromises the phonation of patients and is one of the most important complications of thyroid surgery. For recovering phonation, RLN reconstruction is a highly important and useful technique. Although vocal cord movement...

Objective: This study aimed to elucidate disproportionately low serum thyroglobulin (Tg) values in Tg antibody (TgAb)-positive patients with structural recurrence of papillary thyroid carcinoma (PTC) using liquid chromatography-tandem mass spectrometry (LC-MS/MS). Design: A retrospective study was performed on 176 patients in whom Tg and TgAb level...

Some thyroid tumors that are cytologically diagnosed as benign may be pathologically diagnosed as malignant. Here, we investigated the long-term outcomes of patients with thyroid tumors with benign cytology, and the factors for malignancy. We retrospectively reviewed the cases of 3,102 patients with thyroid tumors >1 cm cytologically diagnosed as b...

Hyalinizing trabecular tumor (HTT) of the thyroid is a mostly benign disease. Its cytological and pathological diagnosis is often difficult, because HTT cells and papillary thyroid carcinoma (PTC) cells share similar features (e.g., intranuclear cytoplasmic inclusions and nuclear grooves). At our institution, 38 patients were diagnosed as or highly...

Identification of the parathyroid glands during surgery is crucial for preventing postoperative hypoparathyroidism. Kikumori et al. reported that the aspartate aminotransferase (AST)/lactate dehydrogenase (LDH) ratio for the saline suspension of a suspicious tissue can differentiate parathyroid tissue from other tissues. The aim of this study was t...

6070 Background: Lenvatinib is now available for unresectable radioactive iodine (RAI)-refractory differentiated thyroid cancer (DTC). However, toxicities are considerable and require frequent dose interruption and modification. Recently, planned drug holidays, which are dose interruptions in accordance with the timing of severe or intolerable adve...

Widely invasive follicular thyroid carcinoma (wi-FTC) is regarded as having an aggressive character and a dire prognosis, but it has not been known whether all wi-FTCs have a dire prognosis. Herein we retrospectively analyzed the cases of 133 patients with wi-FTCs to determine the prognostic significance of vascular invasion and cell-proliferation...

Introduction: Thyroid surgery is a popular and effective treatment for many thyroid diseases, including thyroid cancer. However, patients who undergo thyroid surgery often experience discomfort symptoms such as stretching, pressing, or choking feelings in the neck, headache, shoulder stiffness, and difficulty in moving the neck or shoulders. These...

Background/aim: To date, thyroglobulin-doubling rate (Tg-DR) and tumor volume-doubling rate (TV-DR) of metastatic lesions have been identified as dynamic prognostic factors for differentiated thyroid carcinoma (DTC). In this study, we investigated the prognostic impact for another dynamic factor, the neutrophil-to-lymphocyte ratio (NLR), for DTC w...

Background/aim: Radioactive iodine-refractory differentiated thyroid carcinoma (RR-DTC) has been treated with multi-kinase inhibitors (MKIs), e.g., sorafenib (SOR) and lenvatinib (LEN). We analyzed the outcomes of RR-DTC patients who underwent SOR or LEN treatment at Kuma Hospital. Patients and methods: We enrolled 21 and 18 patients treated wit...

Graves’ disease (GD) may coexist with papillary thyroid microcarcinoma (PTMC). The main purpose of this study was to evaluate whether treatment with radioactive iodine (RAI) may cause acute exacerbation of PTMC concurrent with GD or not. From the medical records of 10,257 GD patients who underwent RAI therapy between 2000–2017, 12 subjects with con...

Persistently detectable serum thyroglobulin (Tg) without residual normal thyroid after a total thyroidectomy for papillary thyroid carcinoma (PTC) indicates biochemically persistent disease, even in patients without detectable lesions on imaging studies. Increasing serum Tg levels reflect progression of the disease. For distant organ metastases, ra...

Importance Small papillary thyroid cancers are the most common type of thyroid cancer, with the incidence increasing across the world. Active surveillance of appropriate cancers has the potential to reduce harm from overtreatment but is a significant de-escalation from prior practice. Mechanisms that inform the rates of retention and adherence have...

Background: The question of how to manage patients with low-risk papillary thyroid microcarcinoma (PTMC; T1aN0M0) has recently become an important clinical issue. Two Japanese centers have conducted prospective clinical trials of active surveillance (AS) for low-risk PTMC since the 1990s, reporting favorable outcomes. This policy has thus seen grad...

We introduce the Japanese reporting system for thyroid aspiration cytology 2019 (JRSTAC2019) proposed by the Japan Association of Endocrine Surgery and the Japanese Society of Thyroid Pathology. Pathological classification and recommended clinical management for thyroid nodules in Japan are different from those described in the World Health Organiz...

Objective: This study aimed to compare the quality of life (QoL) and psychological issues of patients with papillary thyroid microcarcinoma (PMC) who were under active surveillance (AS) and those who underwent immediate surgery (OP). Methods: This was a cross-sectional study conducted on 347 patients with low-risk PMC who were under AS (n = 298) or...

Background: Our previous kinetic analyses of changes in the tumor volume (TV) of papillary thyroid microcarcinomas during active surveillance revealed that the tumors' growth varied over time from rather rapid growth to shrinkage and that the hypothetical TV-doubling rates (DRs) before the patients' presentation were much larger than their observe...

Introduction: Young patients with papillary thyroid carcinoma (PTC) generally have excellent prognoses despite their often-advanced disease status. The reasons for this excellent prognosis are poorly understood. Objective: To investigate the natural history of PTC in young patients, we compared the observed tumor volume-doubling rate (TV-DR) wit...

Noninvasive follicular thyroid neoplasm with papillary-like nuclear features (NIFTP) is a new entity adopted by the newest World Health Organization classification. It is differentiated from follicular variant papillary thyroid carcinoma (FVPTC) and regarded as non-malignant disease. Here, we compared the ultrasound findings of NIFTP (n = 40) with...

Background: Active surveillance for low-risk papillary thyroid microcarcinomas (PMC) is an accepted and safe management strategy. However, some patients undergo conversion surgery after the initiation of active surveillance for various reasons. We investigated the reasons for conversion surgery and whether and how they changed over time. Methods:...

Background Some studies have shown that prophylactic lateral neck dissection (pLND) may be beneficial for patients with papillary thyroid carcinoma (PTC); however, none of the Western guidelines currently recommends this procedure. Since 2007, the decision to perform pLND at our institution has been made on a case-by-case basis with different risk...

The newest WHO classification adopts hobnail variant as an aggressive variant of papillary thyroid carcinoma (PTC). We here report four cases (ages 70–76 years, all females) with hobnail variant PTC treated at Kuma Hospital. Their lesions were cytologically diagnosed as PTC before surgery, but not as hobnail variant. All patients underwent a total...

The aforementioned article was published online (ahead of print) recently in Thyroid. Sawka AM et al. prospectively used standardized medical information to offer a choice between active surveillance (AS) and surgery to eligible patients at their practice in Toronto, Canada, and reported their experiences using a mixed methods analytic approach usi...

Background Our previous kinetic analyses of changes in the tumor volume (TV) of papillary thyroid microcarcinomas during active surveillance revealed that the tumors' growth varied over time from rather rapid growth to shrinkage and that the hypothetical TV-doubling rates (DRs) before the patients' presentation were much larger than their observed...

Background Our previous kinetic analyses of changes in the tumor volume (TV) of papillary thyroid microcarcinomas during active surveillance revealed that the tumors' growth varied over time from rather rapid growth to shrinkage and that the hypothetical TV-doubling rates (DRs) before the patients' presentation were much larger than their observed...

Background: Active surveillance is accepted as a first-line management for patients with low-risk papillary thyroid microcarcinoma (PTMC) without metastasis or extrathyroid extension. While the lung is the most frequent site of distant metastasis of papillary thyroid carcinomas (PTCs), it is unclear if chest computerized tomography (CT) is necessa...

Background Old age is a known prognostic factor for mortality in patients with papillary thyroid carcinoma (PTC). This study aimed to investigate the relationship between cause-specific survival (CSS) following PTC and the extent of old age.Methods We enrolled 4692 patients aged ≥ 55 years with PTC who underwent surgery between 1989 and 2009 at Kum...

Guidelines published by the Japan Association of Endocrine Surgeons (JAES)/Japanese Society of Thyroid Surgery (JSTS) for patients with papillary thyroid carcinoma describe four risk classes (very low-, low-, intermediate- and high-risk) for deciding on therapeutic strategies. Here, we investigate cause-specific survival (CSS) of high- and intermed...

Background: Although papillary thyroid microcarcinoma (PMC) is generally stable on active surveillance, conversion surgery is recommended for enlarging tumors. However, it remains unclear which enlargement threshold should be considered sufficient to trigger surgery. This study analyzed changes in the growth activity of PMC, before and after enlarg...

Background Recently, we have created a revised version of the eighth edition of the tumor–node–metastasis classification for papillary thyroid carcinomas (PTCs) by subdividing the T4a (T4a1 [moderate] and T4a2 [significant]) and N (N1 [N ≤ 3 cm] and N2 [N > 3 cm]) classifications. This re-staging better stratified patient outcomes. In this study, w...

Backgrounds Recently, multi-targeted tyrosine kinase inhibitors(m-TKIs) have become a treatment strategy for radioactive iodine-refractory differentiated thyroid carcinoma (RR-DTC).m-TKIs often require dose reduction or cessation due to various adverse events (AEs). Moreover, these AEs often lose the motivation of patients for the continuation of t...

Background Needle tract implantation (NTI) can occur after thyroid fine-needle aspiration cytology (FNAC). To date, no studies enrolling a large number of patients and studying the cumulative incidence (CI) of NTI have been published. This study analyzed the clinicopathological features of NTI and calculated the CI. Methods A total of 11,745 patie...

Background: Two Japanese prospective trials of active surveillance (AS) for adult patients with low-risk papillary thyroid carcinoma (PTC) ≤1 cm (cT1aN0M0 PTMC) have verified the safety of AS in oncological control and its superiority over immediate surgery with respect to unfavorable outcomes. Thus, AS has been accepted as an alternative to immedi...

Background The eighth edition of the tumor–node–metastasis classification system (TNM-8th) reflects the prognosis of papillary thyroid cancer (PTC) better than the seventh edition. This study investigated methods to further improve the prognostic accuracy of the TNM-8th. Methods We enrolled 5683 patients who underwent surgery for PTC at the Kuma H...

Background: The cribriform-morular variant (CMV) is a rare subtype of papillary thyroid carcinoma (PTC), and is often associated with familial adenomatous polyposis (FAP). This variant is generally indolent, but some aggressive cases have been reported. Patient Findings: We present the case of a 24-year-old woman who underwent total thyroidectomy...

Previous reports by us and other investigators showed that among athyreotic patients on levothyroxine (LT4) following total thyroidectomy patients with normal serum thyroid-stimulating hormone (TSH) levels had mildly low serum free triiodothyronine (FT3) levels, whereas patients with mildly suppressed serum TSH levels had normal serum FT3 levels an...

The definition of papillary microcarcinoma (PMC) by the WHO is papillary thyroid carcinoma (PTC) measuring 10 mm or less regardless of extension to adjacent organs (Ex), clinical lymph node metastasis (N), and distant metastasis (M). Low-risk PMC is defined as PMC without Ex, N, or M. Recent development of imaging techniques, especially ultrasound...

Fine needle aspiration biopsy (FNAB) is the most useful technique available to diagnose thyroid nodules. Recent progress in ultrasound-guided FNAB has enabled us to detect even very small thyroid nodules. Although FNAB is generally a safe technique, several complications have been reported. In this chapter, the prominent complications of FNAB are d...

Background Multitarget kinase inhibitors (m‐TKI), including lenvatinib, are now available as treatment options for radioiodine‐refractory differentiated thyroid cancer (RR‐DTC). However, the optimal timing of treatment initiation with m‐TKI in these patients remains to be defined. Methods We retrospectively reviewed the clinical records of 30 cons...

Importance The burden of concern for patients with thyroid cancer who undergo surgical intervention with or without radioactive iodine is known to be substantial. For patients under active surveillance, this aspect of the patient experience has not been described to date and could be a potential barrier to broader acceptance of surveillance as a ca...

The revised Japan Association of Endocrine Surgeons (JAES)/Japanese Society of Thyroid Surgery (JSTS) guidelines for patients with papillary thyroid carcinoma (PTC) describe four risk classes: very-low-risk, low-risk, intermediate-risk, and high-risk. Here we conducted a retrospective analysis to evaluate the appropriateness of these guidelines’ ri...

Standard therapy for radioactive iodine (RAI)-refractory differentiated thyroid cancer (DTC) is multi-targeted kinase inhibitors (m-TKIs), represented by sorafenib and lenvatinib. One of the main target molecules of m-TKIs is vascular endothelial growth factor receptor (VEGF-R). m-TKIs are known to cause adverse reactions such as hypertension and p...

Background: We report on the growth of papillary microcarcinoma during active surveillance and before clinical presentation. Methods: We conducted a retrospective study of 169 patients with papillary microcarcinoma who were enrolled in active surveillance at our hospital between 2000 and 2004. Patients were followed for a median of 10.1 years us...

Purpose For the differential diagnosis of medullary thyroid carcinoma (MTC) on thyroid nodules, ultrasound-guided fine-needle aspiration cytology is a useful and safe procedure, but its diagnostic accuracy is not high enough. As an ancillary method to accurately diagnose MTC, the calcitonin in fine-needle aspirate washout fluid (FNA-Ct) is used. Ho...

Lenvatinib is a molecular-targeting agent that was recently approved in Japan for treatment of curatively unresectable, radioactive iodine-refractory, progressive differentiated thyroid cancer (DTC). Because only a few Japanese patients have received lenvatinib in clinical trials, there are limited domestic data on its safety and efficacy or progno...

This chapter introduces an active surveillance of very-low-risk papillary thyroid carcinoma (PTC) (T1aN0M0, low-risk papillary microcarcinoma) and surgical strategies for low-risk PTC (T1bN0M0) established by Japanese physicians. Active surveillance is an excellent alternative for therapeutic strategy for very-low-risk PTC, because most of these pa...

Background Based on our long-term observation of medullary thyroid carcinoma (MTC) patients, we hypothesized that some MTCs have spontaneous deceleration or regression of tumor growth over a long term and that a minority may acquire growth acceleration. We thus compared the calcitonin doubling time (Ct-DT) in the earlier and later half-periods of M...

Background: Medullary thyroid carcinoma (MTC) originates from calcitonin-producing cells of the thyroid. In 2009, we published our first report on the biological characteristics and prognosis of 118 MTC patients. Herein, we enrolled a larger number of patients with longer follow-up periods to further study the biological characteristics and approp...

Background Children and adolescents with papillary thyroid carcinomas (PTCs) have generally excellent prognoses despite their frequent extended disease. The tumor growth of young patients' PTCs might show spontaneous slowing postoperatively. We compared young PTC patients' postoperative thyroglobulin-doubling time (Tg-DT) with their preoperative hy...

Sorafenib and lenvatinib showed efficacy for patients with radioactive iodine (RAI)-refractory differentiated thyroid cancer (DTC) in pivotal phase 3 clinical trials. Although the efficacy of lenvatinib in patients who received previous treatment with multi-target kinase inhibitors (m-TKIs), including sorafenib, was reported, the efficacy of sorafe...

Follicular thyroid carcinoma (FTC), a form of differentiated thyroid carcinoma, is the second most common malignancy arising from thyroid follicular cells. Recently, the tumor-node-metastasis (TNM) classification for differentiated thyroid carcinoma was revised from the 7thto the 8thedition. The diagnostic criteria for poorly differentiated carcino...

Purpose The purpose of the study is to clarify the prevalence of calcifications within thyroid tumors on ultrasonography as well as the relationship between the calcification and histopathological types. Materials and Methods Calcifications were classified into 6 (or 8) types according to their shape, size, and region. The prevalence of calcificati...

Background: Active surveillance (AS) of low-risk papillary thyroid microcarcinoma (PMC) was adopted as a management modality in both the Japanese guidelines in 2011 and the American Thyroid Association guidelines in 2015. AS was initiated at Kuma Hospital in 1993 but was not immediately accepted by all physicians. This study investigated the histo...

Introduction: In Japan, prophylactic central node dissection (p-CND) for papillary thyroid carcinoma (PTC) has been routinely performed in many institutions, including ours (Kuma Hospital, Japan). We evaluated the recurrence to a central lymph node in patients with cN0M0 PTC who underwent routine p-CND. Materials and methods: We enrolled 4301 pa...

Introduction: Papillary thyroid carcinoma (PTC) generally shows an excellent prognosis except in cases with aggressive backgrounds or clinicopathological features. Although the cause-specific survival (CSS) of PTC patients has been extensively investigated, the overall survival (OS) of these patients is unclear. We herein investigated both the OS...

Background: We reported that a minority of patients with low-risk papillary microcarcinoma of the thyroid showed disease progression during active surveillance and that older patients had significantly lower disease progression rates than younger patients. Here, we estimated lifetime (≤85 years old) probabilities of disease progression during acti...

Background: Therapeutic options for treating advanced or metastatic medullary thyroid carcinoma (MTC) and anaplastic thyroid carcinoma (ATC) are still limited in Japan, even though vandetanib for MTC and lenvatinib for MTC and ATC have been approved. Sorafenib is an oral multikinase inhibitor approved for the treatment of patients with radioactive...

BACKGROUND: Rapid increases in the incidence of thyroid carcinoma with stable mortality rates from thyroid carcinoma have been reported from many countries, and these increases are thought to be due mostly to the increased detection of small papillary thyroid carcinomas (PTCs), including papillary microcarcinomas (PMCs; i.e., PTCs ≤10 mm). Some res...

Aim: The most frequent recurrence site of papillary thyroid carcinoma (PTC) is the cervical lymph nodes. The introduction of an electric linear probe for use with ultrasonography in 1996 improved preoperative lateral neck evaluations. Before 2006, however, our hospital routinely performed prophylactic modified neck dissection (p-MND) for N0 or N1a...

Papillary microcarcinoma (PMC) of the thyroid is defined as papillary thyroid carcinoma (PTC) measuring ≤1 cm. Many autopsy studies on subjects who died of non-thyroidal diseases reported latent small thyroid carcinoma in up to 5.2% of the subjects. A mass screening study for thyroid cancer in Japanese adult women detected small thyroid cancer in 3...

Background: Some investigators reported that among athyreotic patients on levothyroxine (LT4) monotherapy following total thyroidectomy, the patients with normal serum thyroid-stimulating hormone (TSH) levels had mildly low serum free triiodothyronine (FT3) levels, whereas the patients with mildly suppressed serum TSH levels had normal serum FT3 l...

Background: It is generally considered impossible to differentiate follicular carcinomas from follicular adenomas by means of ultrasonography or cytology before surgery. Therefore, follicular carcinoma is histopathologically diagnosed by verifying capsular and/or vascular invasion after surgery. However, ultrasonography may play an important role...

The incidence of thyroid cancer is increasing rapidly in many countries, resulting in rising societal costs of the care of thyroid cancer. We reported that the active surveillance of low-risk papillary microcarcinoma had less unfavorable events than immediate surgery, while the oncological outcomes of these managements were similarly excellent. Her...

Oxyphilic cell carcinoma is a relatively rare type of differentiated thyroid carcinoma. We investigated the diagnosis of oxyphilic cell carcinoma based on surgical specimens and cytology to elucidate the indications for surgery for oxyphilic tumors. Among 330 patients pathologically diagnosed as having an oxyphilic cell carcinoma or adenoma, the in...

Differentiated thyroid carcinoma (DTC) is generally indolent in nature and, even though it metastasizes to distant organs, the prognosis is normally excellent. In contrast, the overall survival (OS) of patients with radioactive iodine (RAI)-refractory and progressive metastases is dire, because no effective therapies have been available to control...

We investigated the prognostic impact of the Ki-67 labeling index (LI) in minimally invasive follicular thyroid carcinoma (FTC). We enrolled 192 patients (including four with distant metastasis at diagnosis) who were pathologically diagnosed as having minimally invasive FTC between 1998 and 2007 at Kuma Hospital. When the Ki-67 LI was higher than 5...

Differentiated thyroid carcinoma (DTC) is generally indolent in nature and, even though it metastasizes to distant organs, the prognosis is normally excellent. In contrast, the overall survival (OS) of patients with radioactive iodine (RAI)-refractory and progressive metastases is dire, because no effective therapies have been available to control...

Therapy using tyrosine-kinase inhibitors (TKIs) is now available for recurring or advanced medullary thyroid carcinoma (MTC). Here we investigated the calcitonin doubling time (Ct-DT) of MTC patients with distant recurrence postoperatively and for those with distant metastasis at the initial surgery. Of the 13 patients, six died due to the MTC at 5...

Aim: It is difficult to differentiate follicular carcinomas (FC) from follicular adenomas (FA) because ultrasonography and cytology provide very similar findings. FC is histopathologically diagnosed to have capsular and/or vascular invasion. In a few patients, tumor protrusions are observed by preoperative ultrasonography as large forms of capsula...

Objective: Genetic testing for RET germline mutation can be useful to distinguish whether a patient with medullary thyroid carcinoma (MTC) is genuinely sporadic or hereditary. Conducting a routine preoperative germline RET genetic screening for all patients with MTC has the clinical benefit, i.e., avoidance of unnecessary total thyroidectomy in th...

Persistently detectable serum thyroglobulin (Tg) without residual normal thyroid after a total thyroidectomy for papillary thyroid carcinoma (PTC) indicates biochemically persistent disease, even in patients without detectable lesions on imaging studies. Increasing serum Tg levels reflect progression of the disease. For distant organ metastases, ra...