The single thyroid nodule and carcinoma

Assessment of Accuracy of Fine Needle Aspiration Cytology and Ultrasonography in Relation to Histopathology in Cases of Solitary Thyroid Nodule

The thyroid gland is an endocrine gland situated in the lower part of front and the sides of the neck. Thyroid nodules are very common with estimated prevalence that ranges from 4% by palpation to 67% by Ultrasonography. The main purpose of our study was to detect cases of thyroid carcinoma preoperatively in patients with solitary thyroid nodules and subsequently advise surgery in these selected patients only, without missing any malignancy. The goal of the investigating modalities used was that they should detect maximum (ideally all) cases of carcinoma and minimize the number of patients who might end up with unnecessary surgery. The present study was to be undertaken for assessment of accuracy of FNAC & USG in relation to Histopathology in cases of solitary thyroid nodule (accuracy in terms of sensitivity, specificity, positive predictive value, negative predictive value). In our series of total 102 pateints, 90 patients were females (88.2%) and 12 cases were males (11.8%). The overall incidence of malignancy in solitary thyroid nodules is 15.68%. In our series the sensitivity and specificity of Fine needle aspiration cytology and Ultrasonography was 81.25% & 98.84% and 75% and 77.91% respectively. The closest method to ideal was fine needle aspiration cytology. However, a combination of techniques, rather than a single technique, give optimum results & avoid unnecessary surgery in a greater number of patients without missing any malignancy.

Imaging the thyroid

Thyroid imaging has historically relied heavily on scintigraphy, although, not surprisingly in view of the superficial position of the gland, ultrasound has assumed an increasingly prominent role in recent years. The other cross-sectional imaging modalities can also be useful, and the emergence of new radiopharmaceuticals and the increasingly central role of fine needle aspiration cytology have further added to the range of diagnostic techniques available. This review attempts to summarize the current state of knowledge, and makes some suggestions for the most efficient use of imaging resources in the investigation of thyroid disease.

The epidemiology of thyroid disease and implications for screening

The burden of thyroid disease in the general population is enormous. As many as 50% of people in the community have microscopic nodules, 3.5% have occult papillary carcinoma, 15% have palpable goiters, 10% demonstrate an abnormal thyroid-stimulating hormone level, and 5% of women have overt hypothyroidism or hyperthyroidism. Despite this high prevalence of thyroid disease, screening for these disorders is not recommended by any major health agency. This article explores the epidemiologic issues surrounding this complex problem by analyzing prevalence, incidence, and mortality data from a worldwide variety of sources.

Solitary thyroid nodule: a prospective evaluation of nuclear scanning and ultrasonography

The aim of this study was to assess prospectively the value of thyroid nuclear scans and ultrasound examination in the preoperative investigation of patients with a solitary thyroid nodule. Total thyroid lobectomy for a solitary thyroid nodule was performed in 68 cases. Each patient had a thyroid isotope scan (except two women who were pregnant) and thyroid ultrasound examination. There were 10 (15 per cent) malignant nodules, 11 (16 per cent) benign neoplastic nodules and 47 (69 per cent) benign non-neoplastic nodules. All of the patients with malignant nodules who were scanned had a solitary cold nodule on thyroid scan, as did 40 (69 per cent) of those with benign solitary nodules. Ultrasound examination of the thyroid suggested correctly that one of 16 (6 per cent) cystic lesions, four of 16 (25 per cent) complex solid-cystic lesions and three of 18 (17 per cent) of solid lesions were malignant. One lesion reported as multinodular on ultrasonography and one reported as normal also turned out to be malignant. Thyroid isotope scans and ultrasound do not accurately differentiate between benign and malignant conditions and their routine use in the investigation of a solitary thyroid nodule should be abandoned.

Management of the thyroid nodule

The approach to the patient with a palpable solitary thyroid nodule remains controversial. In the rare patient with signs and symptoms suggestive of malignancy, the course of action is reasonably established. However, the patient with an asymptomatic solitary thyroid nodule presents a dilemma. The therapeutic alternatives range from suppressive medical therapy with serial examinations to surgical excision; therefore, to obviate unnecessary surgery, several diagnostic techniques and approaches have evolved which attempt to predict the presence of malignancy. A multitude of articles reflects the widespread disagreement among physicians regarding these diagnostic approaches. Thus, many questions still remain as to the proper management of patients with solitary nodules. The issue is further confounded by problems in assimilating and practically applying the results of the various studies, which often differ in their results. In this report, data regarding the prevalence of the solitary thyroid nodule are reviewed, and the clinical significance of the solitary thyroid nodule is discussed. The problem of management is examined in terms of the various diagnostic approaches to the solitary thyroid nodule: history and physical examination, laboratory tests, ultrasonography, thyroid suppressive therapy, scanning techniques, and fine-needle aspiration. The efficacy of each technique is critically evaluated with an emphasis upon the ability to distinguish benign from malignant disease. The overall aim of this report is to establish a reasonable diagnostic approach to the asymptomatic patient with the solitary palpable thyroid nodule, based upon a critical review of the literature.

Solitary thyroid nodule: diagnosis and management

Thyroid nodules are common. Most are benign lesions since clinically important thyroid carcinoma is a relatively rare disease. The most sensitive and specific test for the diagnosis of thyroid cancer is fine-needle aspiration biopsy, but its diagnostic accuracy depends upon whether or not one excises all suspicious nodules, thus including them as correctly diagnosed. Nevertheless, fine-needle aspiration biopsy is the most sensitive, specific, and cost-effective test for thyroid cancer. Therapy depends upon the cause of the thyroid nodule.

Thyroid nodules and thyroid cancer--diagnostic aspects

The clinical evaluation of patients with thyroid nodules is a common problem confronting the clinician. The vast majority of such nodules are benign, but concern that such a thyroid swelling may harbour malignancy demands prompt and accurate diagnosis. Furthermore, it is clear that properly treated differentiated thyroid carcinoma is associated with an excellent prognosis. The objective of investigating patients presenting with thyroid nodules is to define the small number of malignancies with minimum inconvenience to the patient in the most cost-effective way. There are no laboratory tests which reliably differentiate benign from malignant disease. The traditional approaches of radionuclide and ultrasound scanning have been shown to be poorly specific in the diagnosis of malignancy, resulting in many unnecessary operations for benign lesions. These tests have been replaced in many centres by fine needle aspiration cytology, with surgery for abnormal cytological findings alone. This technique is easily performed in an out-patient clinic and is well tolerated; accuracy in the diagnosis of thyroid neoplasia of up to 97% can be achieved.

Fine needle aspiration biopsy cytology in the diagnosis of thyroid cancer: comparative study of 213 operated patients

Between 1982 and 1984, fine needle aspiration biopsy cytology (ABC) was performed in 1100 patients (aged 14-80, 993 women), with nodular goitre, who had either a solitary cold nodule or dominant hypofunctioning nodule(s) within a multinodular or diffusely enlarged gland. Surgery was performed in 213 patients based on clinical and cytological criteria, and the histology of the surgical specimens was correlated with the cytological findings. ABC specimens were sufficient for cytological diagnosis in 190 patients and were classified as malignant (positive), suspicious or benign. In 37 patients who had a final histological diagnosis of malignancy, cytology was positive or suspicious in 33 and benign in 4. In the remaining 153 patients with benign histology there were 7 positive or suspicious aspirates, and 146 benign. The 37 malignancies included papillary carcinomas in 26 patients (24 positive or suspicious and 2 benign on cytology), Hürthle-cell tumours in 6 (6 positive), follicular carcinoma in 1 (negative), anaplastic carcinoma in 1 (suspicious), medullary carcinoma in 2 (1 positive, 1 negative), and lymphoma in 1 (positive). Our results indicate that the overall sensitivity rate of the ABC method for cancer was 89.2 per cent, the diagnostic specificity 95.4 per cent, the false-positive rate 17.5 per cent and the false negative rate 2.6 per cent. The overall accuracy of the method was 94.2 per cent. It is concluded that papillary and Hürthle-cell carcinomas can be diagnosed accurately with ABC but we recommend that the method be used in conjunction with clinical information and other conventional diagnostic procedures.

Pediatric endocrine surgery

The pediatric surgeon is in a unique position to understand endocrine surgery and, therefore, is expected to develop considerable expertise in this area. In recent years numerous advances and changes have occurred in pediatric endocrine surgery that have led to greater understanding of the disease processes and syndromes and the development of new diagnostic techniques and surgical approaches.

The solitary thyroid nodule: diagnosis and management of malignant disease

While few solitary thyroid nodules are carcinomatous, it is essential to identify and preferentially select those that are for surgery. Clinical, biochemical, serologic, radiographic, scintigraphic, sonographic, biopsy, and even therapeutic evaluation may be necessary to choose those patients with the greatest probability of malignancy. The benefits and limitations of each diagnostic modality are discussed, and the importance of fine-needle aspiration is stressed. After the operative confirmation of malignancy, the prognosis in any given case depends on 1) the histologic type of the neoplasm, 2) its size and extent, 3) the presence of angioinvasiveness, 4) the tendency toward multicentricity of the lesion, 5) the age and sex of the patient, and 6) whether distant metastases are present. These factors influence the extent of surgery required for well-differentiated carcinomas. Meticulous dissection and preservation of the recurrent laryngeal nerves and the parathyroid glands along with their blood supply are important if total thyroidectomy for papillary carcinoma is to be employed with an acceptable operative morbidity to optimize survival. The value of the adjunctive use of thyroid hormone and radioactive iodine is also discussed. Finally, the clinical behaviors and treatments of undifferentiated carcinomas, sarcomas, lymphomas, and neoplasms metastatic to the thyroid gland are reviewed.

Management of thyroid nodules. II: Scanning techniques, thyroid suppressive therapy, and fine needle aspiration

For the differentiation of benign from malignant thyroidal disease, ultrasound displays anatomic but not histologic features. Other visualization techniques can be used including isotope scanning (radioiodine, 99m technetium, 241 americium fluorescence, 131 cesium, 67 gallium, 75 selenomethionine, 201 thallium, 32 phosphorus, 99m Tc-bleomycin, 197 mercury, 133 xenon), thermography, x-ray techniques (plain films, computed tomographic scan, xeroradiography, chest x-ray barium swallow, lymphography, angiography), and thyroid hormone suppression. Needle biopsy can be done by core biopsy (Vim-Silverman and drill biopsy), large needle biopsy for histologic processing and fine needle aspiration for cytologic interpretation. The latter is the safest, most reliable, and most cost-effective technique currently available to differentiate between benign and malignant thyroidal disease and has great promise for the future.

Management of thyroid nodules. I: History and physical examination, blood tests, X-ray tests, and ultrasonography

The approach to the management of the thyroid nodule remains controversial. Confusion exists because virtually any thyroidal disease can present as a clinically solitary nodule which means there is no uniformity regarding natural history, incidence, prevalence, epidemiology, and pathophysiology.. The variety of definitions of thyroid nodules and thyroid carcinoma and the different modes of study selection and individual bias add to the confusion. Diagnostic approaches have not yielded a completely reliable technique to differentiate benign from malignant thyroidal disease. A history of neck irradiation of cervical lymphadenopathy significantly increases the chance of thyroid malignancy, but other parameters of the history or physical examination as well as blood tests are unreliable. Ultrasound displays anatomic but not histologic features. X-ray techniques (plain films, computed tomographic scans, xeroradiography, chest x-ray, barium swallow, lymphography, and angiography) have been used to visualize thyroid nodules, with some techniques proving more useful than others.