Iwao Sugitani

Effect of postoperative thyrotropin suppressive therapy on bone mineral density in patients with papillary thyroid carcinoma: A prospective controlled study

BACKGROUNDnThe influence of thyrotropin (thyroid-stimulating hormone [TSH]) suppressive therapy on bone mineral density (BMD) remains contentious. We have conducted a randomized controlled trial evaluating the effects of postoperative TSH suppressive therapy on disease-free survival for papillary thyroid carcinoma (PTC) since 1996, while prospectively verifying the effects of TSH suppression on BMD.nnnMETHODSnLumbar spine BMD as expressed by T-score was examined annually in female patients randomly assigned to receive TSH suppressive therapy (group A; n = 144) or no therapy (group B; n = 127).nnnRESULTSnThe mean TSH level was 0.07 ± 0.10 mU/L in group A and 3.14 ± 1.69 mU/L in group B. Group B did not show any significant decrease in T-score until 5 years postoperatively, whereas group A had a significant deterioration from 1 year postoperatively. Among group A patients, significant decreases in T-score within 1 year were seen in patients ≥ 50 years of age, but not in those <50 years of age. After 5 years of TSH suppression, 20 patients had T-scores below -2.0 and 100 patients did not. These former patients were significantly older and had lower preoperative BMD measurements than the latter.nnnCONCLUSIONnThis prospective controlled trial suggests that TSH suppression after surgery for PTC has adverse effects on BMD in women ≥ 50 years of age.

Management of low-risk papillary thyroid carcinoma: Unique conventional policy in Japan and our efforts to improve the level of evidence

Papillary thyroid carcinoma (PTC) accounts for over 90% of all thyroid cancers in Japan. The majority of patients with PTC are categorized into a low-risk group according to the recent risk-group classification schemes, and they have excellent outcomes. Several management guidelines for thyroid cancers have been published in Western countries. However, the optimal therapeutic options for PTC remain controversial and high-level clinical evidence to resolve the issues is lacking. Moreover, socioeconomic differences in medical care exist; therefore, conventional policies for the treatment of PTC have been different between Japan and other countries. This report reviews the controversy in the treatment of PTC regarding the initial surgery, postoperative adjuvant therapies, and methods of surveillance. This review focuses on the unique policy in Japan preferring to treat patients with low-risk PTC by a lessthan-total thyroidectomy without adjuvant therapies rather than a total thyroidectomy with radioactive iodine, in an attempt to maintain patients’ quality of life. In addition, the institutional efforts to improve the level of evidence for the management of PTC are introduced, such as a randomized controlled trial for the effect of thyrotropin suppression therapy, a prospective study for selective lymph node dissection based on preoperative ultrasonography, and a prospective nonsurgical observation trial for asymptomatic papillary microcarcinoma.

Cytopathological review of patients that underwent thyroidectomies based on the diagnosis of papillary thyroid carcinoma by fine needle aspiration cytology but were later found to have benign tumors by histopathology

PurposeThe aim of this study is to evaluate the specificity of diagnosing PTC by fine needle aspiration (FNA) cytology.MethodsThis study retrospectively reviewed the cytopathological reports of 1066 patients that underwent thyroidectomy based on a diagnosis of PTC by FNA between January 1993 and December 2008. This study re-evaluated the cytology and histopathology of the patients that received false positive diagnoses of PTC by FNA.ResultsTen patients (0.9xa0%) received false positive diagnoses of PTC by FNA. Three patients were overdiagnosed as having PTC by FNA cytology. In contrast, the nuclear features of PTC in the other seven cases were confirmed by the retrospective reviews of the patients’ FNA cytology. Three of the seven patients showed follicular structures in their resection specimens, thus resulting in a diagnosis of either adenomatous goiter or follicular adenoma. However, PTC could not be diagnosed by histopathology in the remaining four patients, even though the histopathology showed the nuclear features of PTC.ConclusionsMost cases of PTC can be easily diagnosed by cytological and morphological atypia with certain limitations. The difficulty in diagnosing PTC by cytology is because the pathological features of PTC also occur in some benign thyroid tumors. Therefore, immunohistochemical or molecular biological approaches must be combined with current cytological diagnostic techniques for the diagnosis of PTC.

CQ20. When Can Papillary Microcarcinoma (Papillary Carcinoma Measuring 1 cm or Less) Be Observed Without Immediate Surgery

In the past, papillary microcarcinoma was divided into only three categories based on the circumstances of discovery: latent carcinoma (detected on autopsy for reasons other than thyroid carcinoma: prevalence up to 36%), incidental carcinoma (detected on pathological examination for surgical specimens of benign thyroid diseases: the prevalences were reported to be 1.3–22%), and occult carcinoma (lymph node metastasis and/or distant metastasis are detected in advance and small primary lesions in the thyroid are detected thereafter, which is very rare). However, recently, the incidence of microcarcinoma in the clinical setting drastically increased because of the prevalence of mass ultrasonography screening and the development of the fine needle aspiration (FNA) biopsy technique. The prevalence of latent microcarcinoma accounts for 10% of the general population, while the morbidity rate of clinical carcinoma is less than 0.1% and papillary carcinoma shows a generally good prognosis, facilitating a trial observation of incidentally detected microcarcinoma without immediate surgery.

Hemangioma of the Thyroid

Introduction Thyroid hemangioma is very rare, and only a few cases have previously been reported. We encountered a patient with thyroid hemangioma diagnosed after surgery. Case Report A 71-year-old woman visited our hospital with a mass in the left thyroid region. A 5-cm, elastic mass of the thyroid was palpable in the left anterior neck. On cytology by fine-needle aspiration (FNA), the specimen mainly contained blood components without apparent atypical cells. A tumor with abundant blood flow was suspected based on Doppler ultrasonography. Adenomatous goiter was suspected, and subtotal thyroidectomy was performed. A blood clot was present in the tumor, and hemangioma was diagnosed on postoperative histopathological examination. Discussion Preoperative diagnosis of thyroid hemangioma is difficult. However, Doppler ultrasonography and FNA are useful for diagnosis. A differential diagnosis of hemangioma should be considered when blood flow is abundant and only blood components are collected.

PROGNOSTIC VALUE OF THE CALCITONIN-TO-CEA RATIO IN MEDULLARY THYROID CARCINOMA

甲状腺髄様癌では血清calcitonin, CEA値が腫瘍マーカーとして有用であり, calcitonin分泌に比べCEA分泌が優位のものは予後不良であるといわれている。髄様癌におけるcalcitonin/CEA比の予後因子としての有用性について検討した。当科にて経験した髄様癌初取扱い20例 (1986～2004年, 散発性13例, 家族性3家系7例) の5年無再発生存率は80% (再発5例 ; 縦隔4, 頸部3, 肝2), 疾患特異的5年生存率は88% (肝転移の2例が原病死) であった。無再発生存率に影響する予後不良因子として, 術前calcitonin (pg/ml)/CEA (ng/ml) 比10以下, リンパ節転移10個以上が有意であった。術後calcitonin, CEAが正常化した13例には再発を認めなかったが, calcitonin/CEA比が10を超える症例と術後腫瘍マーカー正常化症例とは同一症例であった。calcitonin/CEA比により, 髄様癌の予後を予測することができるものと思われた。

Column 8. The Controversy Regarding the Extent of Thyroidectomy for Papillary Carcinoma and Actual Practice in Japan

There is a significant difference regarding the initial treatment for papillary carcinoma between foreign countries and Japan. In guidelines from Western countries, total thyroidectomy is recommended for most patients with papillary carcinoma and ablation of the remnant thyroid by administrating RAI followed by lifetime TSH suppression by administering levothyroxine is regarded as the standard treatment. In contrast, in Japan, limited thyroidectomy (lobectomy or subtotal thyroidectomy) is widely adopted, especially for low-risk papillary carcinoma, after preoperative investigation of primary lesions and lymph node metastasis on ultrasonography. RAI ablation is only occasionally performed.

CQ16. What Is the Most Appropriate and Convenient Risk Classification System for Predicting the Prognosis of Patients with Papillary Carcinoma

There are high-risk and low-risk groups for cause-specific survival and investigations of many risk factors have been carried out. In representative risk classification systems, several risk factors have been generally identified such as age, gender, extrathyroid extension, tumor size, lymph node metastasis, distant metastasis, and degree of differentiation. Many publications have recommended TNM as the most useful classification system because of its simple evaluation and international prevalence. Taking this background into account, various risk classifications for papillary carcinoma are under review (Tables 1 and 2).

Column 7. What Is the Acceptable Incidence for Persistent Recurrent Laryngeal Nerve Paralysis and Persistent Hypoparathyroidism as Complications of Thyroid Surgery

The incidences of recurrent laryngeal nerve paralysis and hypoparathyroidism vary according to the extent of surgery and whether node dissection is performed. They are also influenced by whether it is primary surgery or repeat surgery. Persistent recurrent laryngeal nerve paralysis was reported to occur in 0.1–0.9% of patients who underwent surgery for benign nodules, indicating that less than 1% is desirable [1–3]. However, the incidence was reported to be 0.5–3.5% of surgery cases with thyroid carcinoma [4–8]. It is speculated that the variability in incidence is due to the variation in the grade of severity of the cases and the variation in the extent of surgery between institutions. The incidence of persistent recurrent laryngeal nerve paralysis ranged from 0.4% to 1.8% for thyroid surgery, including that for benign and malignant diseases, indicating that less than 2% is desirable for thyroid surgery as a whole [9–11]. There are many publications that have not concretely described how the larynx was observed and it is possible that the actual incidence is higher than indicated above.

Column 9. Lobectomy and Paratracheal Node Dissection

It is debatable whether contralateral paratracheal nodes should be dissected when lobectomy is performed for papillary carcinoma. “General Rules for the Description of Thyroid Cancer” published by the Japanese Society of Thyroid Surgery states that dissection of contralateral paratracheal node is not necessary. Since an improvement in prognosis can be expected following therapeutic node dissection, one opinion is that it is better to perform bilateral paratracheal dissection even in lobectomy, while it has been demonstrated that the incidence of re-operation complications in terms of recurrence to the paratracheal nodes increases. Meanwhile, there is another opinion that the contralateral paratracheal node should not be dissected for lobectomy, to avoid adhesion extending to the opposite side in the event that completion total thyroidectomy is needed.