Early diagnosis and detection of clinically non-suspected thyroid neoplasia by the cytologic method: a critical review of 1536 aspiration biopsies

Thyroid fine needle aspiration: how to improve clinicians' confidence and performance with the technique

Studies from single institutions report an acceptable accuracy rate for thyroid fine needle aspiration (FNA). However, FNA accuracy is much lower in many other centers in Europe and the USA and large multicenter studies indicate that the clinicians' confidence in the FNA technique remains low. One explanation for this is that there is an excess of inadequate and indeterminate findings for a follicular nodule at FNA cytology. In a University Hospital with large and qualified experience on thyroid nodule diagnosis, a review of 320 slides with an FNA diagnosis of indeterminate follicular nodule from different minor Italian Hospitals led to a different diagnosis in 61%. Since ancillary thyroid imaging may be overutilized and only a few authors report a proportion of excised nodules lower than 10%, we suspect that use of the FNA procedure is suboptimal. Several techniques are reported to improve the performance of thyroid FNA. Among these are tumor markers and large needle aspiration biopsy (LNAB). Immunodetection of the tumor marker galectin-3 has been evaluated by large multinational studies. Analysis of LNAB specimens reduces the number of inadequate FNA findings, improves the diagnostic determination of indeterminate follicular FNA findings and represents a better substrate for the determination of galectin-3. Therefore, we propose that clinical practice guidelines reflect these adjuvant techniques to thyroid FNA in order to improve selection criteria for thyroid nodule surgery.

Fine needle aspiration and frozen section diagnosis in the management of thyroid nodules

Fine needle aspiration (FNA) is a valuable technique in the evaluation of thyroid nodules. A total of 182 FNAs of the thyroid performed at the Sultan Qaboos University Hospital were reevaluated and 153 were found to be adequate (84%). The cytological results of FNA were divided into neoplastic and non-neoplastic groups. Subsequent histology was obtained in 53 patients with an intraoperative frozen actions (FS) in 27 patients. Papillary carcinoma was found to be the most common, accounting for 70% of these cases with histological follow-up in the neoplastic group. The utility of performing FNA in all thyroid nodules and an intraoperative frozen section only in selected cases is discussed.

The role of aspiration cytology in the management of thyroid nodules

In the hands of an experienced cytologist aspiration cytology is a safe and hitherto the best diagnostic tool in the evaluation of nodular thyroid lesions. In histologically verified case series 50-90% of confirmed thyroid cancers can be detected by aspiration biopsy, the sensitivity being dependent on sampling errors, microscopic misinterpretation and the variation in attitude towards indeterminate diagnosis in the decision for diagnostic surgery. The number of proven benign cases that are correctly identified as such by biopsy varies accordingly and approx. 75% (specificity). In comparison with imaging procedures, including those giving information of functional activity, the combined sensitivity and specificity rates of aspiration cytology come closest to the ideal discriminatory situation. In combination with case history and careful clinical examination, fine needle aspiration cytology is the best guidance for an optimal selection of patients for therapeutic or diagnostic surgery. Future development of sensitive markers for malignant degeneration will probably increase the selective power of this diagnostic technique.

Fine-needle aspiration cytology of malignant lymphoma of the thyroid

Our experience with fine-needle aspiration cytology in five cases of malignant lymphoma of the thyroid is reported. Only one case was correctly diagnosed as malignant lymphoma from the original cytologic reports. Three cases were misdiagnosed as anaplastic carcinoma of small-cell type and two of these three cases were subsequently revised as malignant lymphoma after a second aspiration. The final case was misdiagnosed as chronic thyroiditis at both the first and second aspirations; following a third aspiration, 8 mo later, it was correctly diagnosed as malignant lymphoma. Cytological findings of malignant lymphoma are as follows: many malignant cells are distributed as isolated cells and show monotonous features. Malignant cells are slightly larger than normal lymphocytes. Sometimes cleaved cells or large nucleoli are visible. The differential diagnosis of cytologic findings of malignant lymphoma and the other thyroid diseases is discussed in detail.

A fourteen year practice with the fine needle aspiration biopsy of the thyroid in an endemic area

In our institute from 1970 to 1983 12,829 fine needle aspiration biopsies (FNB) of the thyroid were cytologically examined. Cytologically unsatisfactory specimens were found in 17.7%. 2,709 patients with representative cytological findings were operated and histological examinations were performed. The cytological and histological findings were correlated. There was a false-negative rate of 2.0% and a false-positive rate of 18.4%. Furthermore we divided the results into two time periods (1970-1977 and 1978-1983) because of a change in the indication for surgery in the last years. Although the indication has changed, cytological findings of both time periods investigated were almost similar.

Electron microscopy applied to fine-needle aspiration. A report of six cases from various sites

The authors report the results obtained from the application of electron microscopy techniques to the cytology of fine-needle-aspirated samples of neoplastic lesions from various body sites. These results show that the tissue structure, which is usually lost during the squashing necessary for light microscopy cytology, is preserved when the samples are processed for ultrastructural analysis. Electron microscopy also allows a highly detailed study of the cell's inner structures. Thus, when this technique is applied, fine needle-aspirated samples can be regarded as actual microbiopsies. However, because of the high cost of ultrastructural techniques, we suggest that actual analysis be performed only in selected cases, whereas fixation and inclusion for electron microscopy could be done routinely.

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.