Incidental carcinoma in multinodular goiter: risk factors

The aim of the study was to analyze the frequency of incidental thyroid carcinoma (unknown tumor smaller than or equal to 10 mm) in a consecutive series of 462 total thyroidectomies for multinodular goiter and to investigate the clinical risk factors for this type of malignancy. A retrospective, single-center study of outcome data collected from patients with preoperative diagnosis of multinodular goiter who underwent total thyroidectomy at the General Surgery Unit of Pavia (Italy) between January 2000 and December 2008 was performed. Possible risk factors for malignancy were: gender, age, time of evolution of goiter, presence of a dominant nodule in multinodular goiter, hyperthyroidism, history of radiation to the neck, residence in an area of endemic goiter, prior thyroid surgery, calcifications in the goiter detected by neck ultrasound or chest X-rays, and a family history of thyroid diseases. In a 9-year period, 462 patients underwent total thyroidectomy. We found 41 cases of incidental thyroid carcinoma; the most common histopathological type was papillary. The multivariable analysis demonstrated that the clinical variables associated with occult carcinoma were a personal history of radiation therapy to the neck, the presence of calcifications detected by ultrasound or neck X-rays, and a family history of thyroid diseases; residence in an area of endemic goiter was a protective factor. A personal history of radiation to the neck, detection of calcifications by ultrasound or by neck X-rays, and a family history of thyroid diseases should be considered clinical risk factors for malignancy in multinodular goiter.     

Characteristics of well-differentiated thyroid cancer associated with multinodular goiter

BACKGROUND: The likelihood of thyroid cancer is similar in patients with one or more nodules, but tumor characteristics of thyroid cancer in glands with multinodular goiter are unclear. MATERIALS AND METHODS: This study consisted of 100 consecutive patients (ages 15-81 years; 84 women), who underwent thyroidectomy for papillary or follicular thyroid carcinoma between 2005 and 2006. Patient demographics, diagnostic tests, operations, and pathological findings were reviewed. RESULTS: In a univariate analysis, cancer diagnosed within multinodular goiter was different from solitary cancer nodule in age of diagnosis (48 vs 40 years, p = 0.002), tumor size (1.42 vs 2.20 cm, p = 0.024), and the presence of cervical lymph node metastases (p = 0.035). There was no difference in gender, extrathyroidal invasion, multifocality, and types of operation. Only age (odds ratio, 1.056) and tumor size (odds ratio, 0.730) revealed independent correlation in multivariate analysis. CONCLUSION: Thyroid cancer in glands with multiple nodules is associated with older age at diagnosis and smaller tumor size.     

Total Thyroidectomy for Benign Thyroid Disorders in an Endemic Region

Total thyroidectomy is increasingly being accepted as a treatment of choice for differentiated thyroid cancer. However, because of presumed increased morbidity associated with this procedure, it is still not considered a viable option for management of benign thyroid disorders. To assess the safety and efficacy of total thyroidectomy for management of benign thyroid disorders, we analyzed our data from 127 total thyroidectomies performed for benign thyroid disorders. Demographic details, biochemical findings, indications for operation, specimen weight, and complications were noted. Among these patients, 52 had a toxic goiter and 75 had a nontoxic goiter. The mean duration of the goiters being present was 6.08 ± 6.06 years (0.9–26.0 years), and the mean weight of the specimens was 136.88 ± 120.68 g. The incidence of occult malignancy was 6.3% (n= 8), and those of permanent hypothyroidism and permanent recurrent laryngeal nerve palsy were 1.6% and 0.8%, respectively. Total thyroidectomy should be considered a treatment of choice for multinodular goiter and Graves' disease in a setting of palpable nodule(s) or ophthalmopathy (or both). It is particularly relevant in endemic regions where patients present with a long-standing, large nodular goiter with virtually no normal thyroid tissue. Reoperation for recurrent goiter in such a setting would be fraught with distressing complications.     

Thyroid disease in children and adolescents

Thyroid diseases in children and adolescents are not common. The present paper describes 73 patients, aged 5 to 18 years, who had thyroid disease which was treated by surgery. Of these, 18 had diffuse simple goiter, 11 had diffuse toxic goiter and 44 had nodular goiter. Of those patients with nodular goiter, 34 had adenomatous goiter, one had lymphocytic thyroiditis, one had lymphosarcoma and eight had cancer. In the patients with nodular goiter under the age of ten years, 40% had cancer, and of those aged 11 to 18 years, 14.7% had cancer. Thyroid nodules were more frequent in girls than in boys, but the incidence of cancer in nodular goiter was higher in boys than in girls.     

Thyroid cancer with concurrent hyperthyroidism

OBJECTIVE: To study the clinical manifestation, outcome, and factors predicting metastases in patients with thyroid cancer and concurrent hyperthyroidism. DESIGN: Retrospective study of 37 thyrotoxic patients with differentiated carcinomas of the thyroid who were operated on between 1979 and 1995. The follow-up period ranged from 562 days to 14 years 9 months (mean +/- SE, 2093+/-201 days). SETTING: University hospital with an annual performance rate of about 700 thyroid operations. PATIENTS: Thyroidectomy was performed in 37 patients (31 women and 6 men), including 33 papillary carcinomas and 4 follicular carcinomas. The mean +/- SE age of the patients was 38.6+/-2.2 years. RESULTS: The mean +/- SE diameter of tumors was 13.2+/-0.9 mm (range, 2-67 mm). The tumor size in 25 patients (68%) was 10 mm or smaller. Subtotal thyroidectomy (21 patients), total thyroidectomy (8 patients), near-total thyroidectomy (4 patients), and completion thyroidectomy (4 patients) were performed. Twenty-eight patients underwent postoperative sodium iodide I 131 (131I) ablation for thyroid remnant. There was 1 local recurrence, 3 metastases to regional neck lymph nodes, and 3 distant metastases. A patient with follicular carcinoma died of metastases at 3 years 4 months after thyroidectomy. Age, sex, duration of thyrotoxic symptoms, tumor size, histopathological findings, type of goiter, extent of surgery, 131I ablation, and 6-week postoperative serum concentrations of thyroglobulin or thyrotropin were not significant factors in predicting metastases. Serum levels of triiodothyronine and thyroxine before antithyroid treatment in the patients with metastases were significantly higher than in those without metastases. CONCLUSION: The majority of patients with thyroid cancer and concurrent hyperthyroidism have small carcinomas.     

Substernal goiter

The literature on substernal goiter from the seventeenth century to the present is reviewed. Substernal goiter may be defined as any thyroid enlargement that has its greater mass inferior to the thoracic inlet. Truly ectopic mediastinal goiters are rare, and most substernal goiters arise from and maintain some attachment to the cervical thyroid gland. Patients are generally in the fifth decade of life, and women predominate. Most patients experience dyspnea, stridor, or dysphagia, but 15 to 50% are asymptomatic; symptoms are often positional, and acute stridor may occur. Ten to twenty percent have no cervical mass or tracheal deviation on examination, and virtually all patients are euthyroid. Standard chest roentgenograms are often diagnostic, but computed tomographic or radioactive iodine scans may be helpful. The presence of a substernal goiter in all but the highest-risk patients is an indication for resection, usually through a cervical collar incision; an occasional patient will require sternotomy or thoracotomy. Death or major complications should be rare postoperatively. Substernal goiters are adenomatous and benign, but carcinoma occurs in 2 to 3% and may be occult. Patients should be followed closely, as these goiters may recur.     

Measurement of cellular DNA content in thyroid tumors by the flow cytometer

Cellular DNA contents measured by flow cytometer were analysed in relation to histopathological classification and clinicopathological findings in 94 patients with thyroid tumors. The DNA determination was carried out on both tumor tissues and surrounding thyroid tissues. As an indicator of tumor growth, proliferative index (PI) and DNA index were calculated from DNA histograms. The PI value (mean +/- SD) was 32.5 in medullary carcinoma, 31.3 +/- 10.2 in follicular carcinoma, 28.2 +/- 6.2 in papillary carcinoma, 21.6 +/- 4.4 in follicular adenoma, and 20.6 +/- 4.4 in adenomatous goiter, respectively, whereas the value in normal thyroid tissues was 4.1 +/- 2.2. PI values in the surrounding thyroid tissues in cases of follicular and papillary carcinomas were significantly (p less than 0.01) lower than those of the corresponding cancer tissues, but they were higher than that of the normal tissues. The DNA index and frequencies of aneuploidy were 1.15 and 50.0% in medullary carcinoma; 1.25 +/- 0.27 and 66.7% in follicular carcinoma; 1.19 +/- 0.25 and 64.2% in papillary carcinoma; 1.01 +/- 0.04 and 9.3% in follicular adenoma; and 1.00 +/- 0.00% in adenomatous goiter. The result implies that PI value and DNA index are relatively correlated with clinicopathological criteria of malignancy of individual thyroid tumors, and they may become a putative tool for determination of the biological malignancy.     

Adenomatous polyposis: an association with carcinoma of the thyroid

A review of the St Mark's Hospital Polyposis Registry has revealed an association between adenomatous polyposis (familial polyposis coli) and thyroid carcinoma. Even though full clinical information was unavailable on all patients in the registry, it is evident that young women (below 35 years of age) are at particular risk of developing thyroid cancer, mainly of a papillary type, their chances of being affected being approximately 160 times that of normal individuals. All patients with adenomatous polyposis should thus have regular thyroid examination.     

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??Coexisting nodular goiter and thyroid carcinoma: a retrospective analysis of 262 cases HE Liang, ZHANG Hao??DONG Wen-wu, et al. Department of General Surgery, the First Hospital, China Medical University, Shenyang 110001, China
Corresponding author: ZHANG Hao,E-mail: haozhang@mail.cmu.edu.cn
Abstract Objective To summarize the clinical characteristics and the highlight of diagnosis and treatment of nodular goiter in patients with coexistent thyroid carcinoma??Methods A total of 262 nodular goiter coexisting with thyroid carcinoma patients underwent operations from January 1998 to December 2007 at the First Hospital, China Medical University were retrospectively reviewed??Results Two hundreds and sixty-two patients accounted for 33.9% in thyroid carcinoma patients at the same time. The age mainly ranged from 40 to 59 years. The sex ratio was 1:5.2 (male:female). The clinical characteristics were manifested as nodular goiter. In addition to 25 patients who received secondary operation had a clear diagnosis before surgery. 70.0% of tumors were suspected as malignant lesions by preoperative ultrasound examination, in which 39.2% exhibited as microcalcification. The accuracy rate of intra-operative fast frozen section pathological examination was 93.2%. Tumor nodules less than 2.0 cm in diameter accounted for 62.9%, and microcarcinomas accounted for 40.1%. Clinical phase I cases accounted for 74%. The main pathological type was papillary carcinoma??93.1%??. The various styles of thyroidectomy were performed according to the different pathological results?? Neck dissection was performed in 122 patients, and 46 of them had cervical lymph node metastasis. Conclusion Most patients with coexisting thyroid carcinomas and nodular goiter have small tumor size and lower incidence of lymph node metastasis. The coexistent thyroid carcinoma was often well differentiated papillary cancer??The preoperative ultrasonography and the intra-operative fast frozen section examination are helpful for the diagnosis of thyroid carcinoma in nodular goiter?? Regular follow-up in patients with nodular goiter could improve the early diagnostic rate of coexisting thyroid carcinoma.     

Video-assisted thyroid lobectomy through a small wound in the submandibular area

BACKGROUND: Endoscopic thyroidectomy has not gained wide acceptance because of the expertise required, the long operation time, the wide dissection, and the extra cost of specialized instruments. We developed a video-assisted hemithyroidectomy procedure that requires only one small incision at the upper neck. METHODS: Hemithyroidectomy was performed through a 25 to 30 mm transverse incision made in the upper lateral neck for the treatment of benign thyroid nodule. No gas or external lift dissection was needed. RESULTS: The mean age of 39 patients was 33.8 years. The tumor size ranged from 1.9 to 5.5 cm (mean 3.1 cm). All patients underwent total lobectomy without conversion to traditional cervicotomy. The mean operation time was 56 minutes (range 36 to 90). Follicular adenoma was the final pathologic diagnosis in 25 patients and adenomatous goiter in 14. Transient recurrent laryngeal nerve palsy was seen in 1 patient. CONCLUSIONS: Our technique is safe, minimally invasive, less time consuming, and cosmetically excellent.     

Incidental thyroid carcinoma in patients with Graves' disease

BACKGROUND: The clinical significance of incidental thyroid carcinoma in patients with Graves' disease is uncertain. METHODS: The prevalence of incidental thyroid carcinoma was determined in patients with Graves' disease who underwent surgery from 1990 to 2007 and was compared with patients with nontoxic nodular goiter or toxic multinodular goiter who underwent surgery during the same time period. RESULTS: Of the 93 patients who underwent thyroidectomy for Graves' disease, 2 patients (2.2%) had an incidental papillary carcinoma: .4 and .5 cm in size. Neither patient developed recurrent disease after 3 and 13 years of follow-up evaluation. The prevalence of incidental thyroid cancer was 3.6% and 6.2% in patients with nontoxic nodular goiter and toxic multinodular goiter, respectively (P = not significant). CONCLUSIONS: The prevalence of incidental thyroid carcinoma in patients with Graves' disease is comparable with patients with nontoxic or toxic goiter. Incidental thyroid carcinomas in patients with Graves' disease were papillary microcarcinomas of no clinical consequence.     

Expression of Vascular Endothelial Growth Factor and Presence of Angiovascular Cells in Tissues from Different Thyroid Disorders

Background

Vascular endothelial growth factor (VEGF) is involved in tumor angiogenesis and other pathophysiological processes.

Materials and methods

We studied the localization of VEGF in human thyroid tissues to clarify its involvement in proliferative processes in a variety of thyroid disorders. Immunohistochemical analysis using purified rabbit polyclonal anti-human VEGF or anti-human CD34 antibody and a streptavidin–biotin peroxidase complex detection system was performed on 58 tissue specimens from 53 patients with different thyroid disorders and 5 normal thyroid glands.

Results

Vascular endothelial growth factor was not detected in normal thyroid follicular cells. However, some thyroid tumor cells expressed VEGF in the cytoplasm (papillary carcinoma, 10/18; follicular carcinoma, 1/3; medullary carcinoma, 2/2; follicular adenoma, 3/11; adenomatous goiter, 2/4). In benign follicular adenoma and adenomatous goiter, weak expression of VEGF was found in small areas of the tumor, whereas in malignant thyroid tumors, it was strongly expressed in many cells. However, VEGF was not expressed in anaplastic carcinoma, malignant lymphoma, or Graves’ disease. Angiovascular cells stained with CD34 antibody in tissues from different thyroid disorders reflected statistically significant differences in papillary carcinoma, follicular adenoma, and Graves’ disease compared with normal thyroids, and such cells showed a trend toward increases in medullary carcinoma and adenomatous goiter. In contrast, low vascularity was observed in anaplastic carcinoma, malignant lymphoma, and follicular carcinoma.

Conclusions

Because VEGF probably functions as a hypoxia-inducible angiogenic factor, overexpression of this mediator, concomitant with hypervascularity, may be induced more strongly in malignant thyroid tumors, which need more oxygen to proliferate, than in benign follicular tumors. However, neither VEGF nor CD34 was expressed in anaplastic thyroid carcinoma, which is an extremely poorly differentiated malignant tumor. CD34 but not VEGF was expressed in the hyperplastic thyroid tissues of Graves’ disease composed of nontransformed cells. Thus, the expression of VEGF concomitant with CD34 is suggested to reflect both the transformation and differentiation state of malignant tumors.     

影响甲状腺乳头状癌颈侧淋巴结转移的高危因素

目的探讨影响甲状腺乳头状癌(PTC)颈侧淋巴结转移的高危因素。方法选择2011-01-2018-03间在云浮市人民医院接受手术的120例PTC患者,对其临床资料进行回顾性分析。结果 120例患者中颈侧淋巴结转移82例,其中79例(96.3%)为中央区转移、3例(3.7%)为侧颈部淋巴结转移。PTC颈侧淋巴结转移的发生与性别、原发病灶大小、肿瘤位置、合并结节性甲状腺肿、合并桥本甲状腺炎等因素密切相关(P<0.05)。结论 PTC颈侧淋巴结转移高发人群为男性,肿瘤的大小、位置、合并结节性甲状腺肿、合并桥本甲状腺炎,均为影响PTC颈侧淋巴结转移的高危因素。     

Cervico-mediastinal extension of thyroid cancer

A surgical series of 30 cervico-mediastinal thyroid cancer patients operated on has been retrospectively reviewed. Results were compared with those obtained in patients operated on for benign cervico-mediastinal goiter and thyroid cancer confined to cervical region. Of 4688 thyroidectomies performed, 30 patients were operated on for thyroid carcinoma with cervico-mediastinal extension. There were 15 males and 15 females. The mean age was 67 years (range, 21-86 years). Patients with cervico-mediastinal cancer were significantly older than patients with benign cervico-mediastinal goiter (P < 0.0001). Time between onset of first symptoms and surgery was significantly longer in patients with cervico-mediastinal cancer than in those with benign cervico-mediastinal goiter (P < 0.0001) and cervical thyroid cancer. Signs and symptoms at the time of surgery were cervical mass in 28 patients (93%), cervical lymphadenopathy in 20 patients (66%), dyspnea in 21 (70%), dysphagia in 9 (30%), dysphonia in 2 (7%), and venous stasis in 1 (3%). None of the patients was asymptomatic. Total thyroidectomy with functional lymphectomy was performed in 16 cases. Seven of these patients were operated on in 2 stages. In 8 cases the operation was a debulking procedure, and in 6 it was a near-total thyroidectomy. Sternotomy was performed in two cases. A differentiated thyroid cancer was found in 21 patients (70%), medullary in 5 (17%) and undifferentiated in 4 (13%). The incidence of medullary carcinoma was significantly higher compared with cervical cancer (P < 0.008). Postoperative complications were higher than those occurring in benign cervico-mediastinal goiter and similar to those occurring in cervical cancer. The actuarial survival was similar to that of cervical cancer matched for age and sex. This analysis shows that the longer clinical history of goiter is related to its endothoracic development and its neoplastic transformation. This finding should further encourage surgeons to treat any cervico-mediastinal goiter as promptly as possible.     

TSH suppression in the management of thyroid nodules and thyroid cancer

Clinical and experimental data concerning TSH suppression, by giving exogenous thyroid hormone, in patients with goiter and in patients with thyroid cancer show a beneficial effect. In the goiter patients, TSH suppressive therapy seems most effective in young patients with diffuse or newly discovered goiters, in hypothyroid patients, and in patients with chronic lymphocytic thyroiditis or compensatory thyroid hypertrophy after partial thyroidectomy. With TSH suppressive therapy about 2/3 of thyroid nodules become smaller, but only about 5% to 10% disappear. In patients with differentiated thyroid cancer (papillary, mixed papillary-follicular, and follicular), tumor recurrence, tumor progression, and long-term survival all seem to be influenced favorably by TSH suppressive therapy. Experimental investigations demonstrate that both benign thyroid adenomas and differentiated thyroid carcinomas have TSH receptors situated on the plasma membranes. These TSH receptors appear to be coupled to the activation of adenylate cyclase in a one-to-one relationship. Experimental and clinical studies strongly support the use of thyroid hormone both for the treatment of patients after thyroidectomy for thyroid cancer and as prophylaxis to prevent the development of thyroid cancer in high-risk irradiated patients. The dose of thyroxine recommended for adequate TSH suppression is the lowest dose of thyroxine that will completely block the TSH response to TRH (usually 0.2 to 0.25 mg).Supported in part by a grant from the Veterans Administration.     

HMGB-1和TSGF联合检测诊断甲状腺癌的价值

目的:探讨高迁移率蛋白1(HMGB-1)和肿瘤特异性生长因子(TSGF)联合检测诊断甲状腺癌的临床价值。方法:使用ELISA试剂盒检验86例经病理证实的甲状腺癌患者,78例结节性甲状腺肿患者和69例健康人对照组的血浆HMGB-1和TSGF水平。分析血浆HMGB-1及TSGF水平与临床病理参数间的关系。结果:TSGF和HMGB-1在3组之间的差异具有统计学意义(均P<0.05),以甲状腺癌最高,结节性甲状腺肿次之,健康人最低。HMGB-1/TSGF的曲线下面积为0.912,联合检测对甲状腺癌的诊断价值大于HMGB-1和TSGF单独检测(均P<0.05)。甲状腺癌患者血浆HMGB-1及TSGF水平与患者性别、年龄、淋巴结转移及临床分期无关(均P>0.05)。结论:HMGB-1与TSGF联合检测对甲状腺癌的早期诊断有一定的应用价值。     

甲状腺癌与甲状腺自身抗体的关系

目的 分析患者甲状腺过氧化物酶抗体(TPOAb)和甲状腺球蛋白抗体(TGAb)水平与甲状腺癌的关系.方法 选取2001年1月至2009年12月手术治疗的分化型甲状腺癌患者283例为研究组,同期结节性甲状腺肿患者500例为对照组,分析甲状腺自身抗体是否是甲状腺癌的危险因素.将甲状腺癌患者按有无淋巴结转移分组,比较两组间甲状腺自身抗体阳性率差异.结果 多因素logostic回归分析与甲状腺癌相关的独立危险因素为肿物较小、TGAb升高和TSH升高.伴淋巴结转移的甲状腺癌患者TCAb阳性率明显高于无淋巴结转移患者(P＜0.05).结论 TGAb可能是与甲状腺癌相关的预测因子,在甲状腺癌患者中增高提示淋巴结转移可能.     

甲状腺微小癌的临床研究

目的 探讨甲状腺微小癌的临床特征及治疗原则.方法 回顾分析1997年1月至2006年12月收治的311例甲状腺微小癌的临床资料.结果 181例患者以结节性甲状腺肿、甲状腺瘤等良性病变为首发症状(偶发组),130例患者以甲状腺癌结节或体检B超怀疑恶性病变或以颈部淋巴结转移为首发症状(显性组).两组平均年龄分别为47岁及42岁(F=15.545,P=0.000).显性组恶性程度高于偶发组,其需行颈淋巴结清扫的比例分别为48.5%(63/130)及30.9%(56/181),颈部淋巴结转移率分别为27.7%(36/130)及10.5%(19/181),肿瘤两叶多发病灶分别为18.5%(24/130)及9.4%(17/181).结论 将甲状腺微小癌分为"偶发癌"和"显性癌"两个亚型对认识微小癌的发生、发展及指导临床治疗具有实际意义.对"显性癌"患者,患侧腺叶切除或甲状腺全切除应视为标准术式;而对"偶发癌"患者,在保证安全切缘的前提下,甲状腺次全或腺叶切除都可视为手术选择.同时应常规探查Ⅵ区淋巴结,肿大者应予以清扫,体检及B超提示颈淋巴结转移者需再加颈侧清扫.     

Benefit of Ultrasonography in the Detection of Clinically and Mammographically Occult Breast Cancer

Objective  The purpose of this study was to evaluate the performance of high-resolution ultrasonography in the detection of clinically and mammographically occult breast cancer. Materials and methods  From September 2003 to November 2006, a total of 1485 patients were confirmed to have in situ or invasive breast cancer in Hong Kong Sanatorium and Hospital Breast Care Centre. All patients underwent mammography (MMG) and/ or sonography (USG) evaluation. Patients’ age and size of tumor detected by USG alone were compared with those detected by MMG. Results  Altogether, 222 patients (17%) had positive imaging findings on USG only, among which 22 (13%) patients had nonpalpable tumors. Performing USG increased the cancer detection rate among clinically and mammographically occult breast lesions by 14.3%. The mean size of the tumors detected only by USG was 1.98 cm, which was not significantly different from the mean size of tumor detected by MMG (1.46) (p = 0.23). This remains true in the group of patients with nonpalpable tumors (1.36 vs. 1.46 cm, p = 0.88). The sensitivity of USG is 91%, which is significantly higher than that of MMG (78%) (p = 0.001). This remains true in patients age <40 or ≥40, tumor grading I toIII, and LVI +/− cases. However, MMG had higher sensitivity in the group of patients with nonpalpable tumors (73% vs. 62%, p = 0.01) and noninvasive cancers (72% vs. 69%, p = 0.01). Conclusions  The use of high-resolution USG may lead to detection of a significant number of occult cancers that are no different in size from nonpalpable mammographically detected lesions.     

The localization of parathyroid tissue by ultrasound scanning prior to surgery in patients with hyperparathyroidism

Ultrasonic localization of parathyroid tissue has been attempted in 24 patients with hyperparathyroidism prior to surgical exploration of the neck. All 24 patients had biochemically proven hyperparathyroidism. Standard contact diagnostic ultrasound equipment fitted with a 5 MHz transducer was used, and transverse and longitudinal scans of the region of the thyroid gland were performed at 5 mm intervals. The normal anatomical structures identified were the lobes of the thyroid gland, trachea, common carotid arteries, and jugular veins. The longus colli muscle on each side was used as a major landmark. These structures define the site where most parathyroid glands are found in the neck. In 18 of the 24 patients the suspected parathyroid tumor was visualized preoperatively and confirmed at operation. The abnormal glands ranged in size from 5 to 12 mm in transverse diameter. In 3 patients false-positive diagnoses were made by ultrasound; at operation the abnormalities proved to be thyroid nodules protruding from the posterior surface of the thyroid gland. Ultrasonography is of little value in the presence of multinodular goiter. Three adenomas and 3 hyperplastic parathyroid glands greater than 5 mm in diameter were not identified. Localization of enlarged parathyroid glands by echography may be difficult when normal anatomical landmarks are altered by the presence of multinodular goiter or because of previous surgery. The sensitivity of this technique for identifying in the neck parathyroid glands larger than 5 mm in diameter was found to be 79.3% with 11.5% false-positive and 8.6% falsenegative results.