Bactericidal activity of a fermented hot-water extract from Stevia rebaudiana Bertoni towards enterohemorrhagic Escherichia coli O157:H7 and other food-borne pathogenic bacteria

AIMS: To evaluate the correlation of fine needle aspiration (FNA) cytology and frozen section biopsy in the diagnosis of thyroid nodules. METHODS: The medical records of 662 patients who underwent FNA cytology of the thyroid and thyroid surgery were analysed. Frozen section biopsies were taken from 586 of the 662 patients. The diagnostic correlations of FNA cytology, frozen section, and both FNA cytology and frozen section with definitive histological assessment were evaluated. RESULTS: Among the 662 patients who received FNA cytology, there were 356 cases (53.8%) diagnosed as benign, 114 cases (17.2%) as malignant, 148 cases (22.4%) as indeterminate, and 44 cases (6.6%) as unsatisfactory. The positive predictive value for the detection of malignancy by FNA cytology was 92.1% and the negative predictive value was 95.2%. The incidence of malignancy in the indeterminate cytological diagnosis was 23%. The diagnosis from frozen sections was benign in 445 cases (75.9%), malignant in 134 cases (22.9%), and deferred in 7 cases (1.2%). By frozen section, the positive and negative predictive values were 97% and 95.5%, respectively. Diagnostic accuracy up to 98% was achieved when FNA cytology and frozen section diagnoses were in agreement. No false positives were observed when FNA cytology and frozen sections were both positive for malignancy. When FNA cytology and frozen section diagnoses were discordant, frozen section showed a higher accuracy (78.9%) than FNA cytology (21.1%). In the face of an indeterminate or unsatisfactory cytological diagnosis, the diagnostic accuracy of frozen sections reached 92.6%. CONCLUSIONS: The results confirm that FNA cytology is a useful tool in the initial evaluation of thyroid nodules. Intraoperative frozen section is a valuable procedure to confirm the cytological diagnosis and identify malignancy in patients with indeterminate or unsatisfactory cytological diagnosis. With reliance on frozen sections as an intraoperative guide of thyroid surgery, the possibility of unnecessary extensive surgery and the need for the second operation are considerably lower.     

Telomerase activity in the differential diagnosis of papillary carcinoma of the thyroid

BACKGROUND: Although fine-needle aspiration (FNA) is 90% sensitive in the detection of papillary carcinoma (PC) of the thyroid, its specificity has been reported as low as 52%. Consequently, patients who have an FNA suspicious for PC may undergo operation for a benign process. The ribonucleoprotein telomerase has been noted to be activated in a wide variety of carcinomas. We examined 30 PCs for telomerase activity to determine whether this would be a useful adjunct to FNA in the diagnosis of lesions suspicious for PC. METHODS: Standard telomere repeat amplification protocol assays were performed on fresh frozen tissue samples from 30 PCs, 3 benign nodules, and 10 normal thyroids. RESULTS: Telomerase activity was documented in 20 of 30 (67%) of the PCs, 0 of 3 benign nodules, and 0 of 10 normal thyroids. In all, 11 of the 20 PCs had FNA cytology that was nondiagnostic of PC, and 2 of the benign nodules had FNA that was suspicious for PC. CONCLUSIONS: The telomerase assay appears useful in the distinction of benign from malignant thyroid lesions that have FNA suspicious for but not diagnostic of PC. On the basis of these findings, a prospective trial examining telomerase activity in FNAs suspicious for thyroid cancer has been initiated.     

Pediatric thyroid nodules: management in the era of fine needle aspiration

BACKGROUND/PURPOSE: Thyroid nodules are rare in children. The need to uncover malignancy is the most challenging dilemma in management. The aim of this report was to determine whether management of pediatric thyroid nodules has changed in the era of fine-needle aspiration (FNA) cytology. METHODS: Twenty-four children with thyroid nodules comprised the study group. Demographic characteristics, clinical manifestations, imaging results, FNA cytology results, surgical therapy, complications, and pathological reports were reviewed retrospectively. FNA cytology results were categorized as either benign, malignant, suspicious, or insufficient. RESULTS: Girls outnumbered boys (five to one) with a mean age of 14.9 years. Nineteen nodules were benign and five malignant. Malignancy was characterized by localized tenderness, multiglandular appearance, and fixation to adjacent tissues. Ultrasound scans and nuclear scans gave no clue toward management because cystic, hot, and warm nodules figured among malignant cases. FNA in 18 children achieved 80% accuracy, 60% sensitivity, 90% specificity, 75% positive, and 81% negative predictive value. Physical examination findings, persistence of the nodule, and progressive growth decided for surgery in most children. CONCLUSIONS: FNA is a safe adjunctive test that plays a minor role in the decision to withhold surgery. Its greatest strength is to resolve, in case of suspicious or malignant cytology, that a more radical procedure will be needed. Clinical judgement as determined by serial physical findings continues to be the most important factor in the management of thyroid nodules in children.     

Proton and chloride currents in Chinese hamster ovary cells

Despite being one of the most frequent neoplasms occurring in the endocrine system, thyroid carcinoma is, nevertheless, a relatively rare event (0.5-1.5% of all malignant tumours in man); the differentiated forms are the most prevalent and are characterized by a high mean survival rate, whereas the very aggressive forms are rare and prognosis is unfavourable. Diagnostic evaluation of carcinomatous lesions, particularly in the early stages, may give rise to considerable difficulties at a clinical level due to the differentiation of the benign lesions, which are a frequent finding. The traditional clinico-semeiological and instrumental parameters, which, in the past, were used in the assessment of suspected malignancy, should not be considered as markers of malignancy; however, exposure to ionizing radiations during childhood may have a well defined role of risk. Following the recent progress in genetic and molecular studies, it is now possible to exploit genetic-molecular tumor markers and, at present, thyroid medullary carcinoma may be identified also in the absence of clinical evidence, particularly the familial form, thus allowing suitable prophylaxis in those subjects with specific genetic impairment (e.g. preventive thyroidectomy in infancy). Since no discriminating clinico-semeiological parameters are available, considering the aspecificity of scintigraphic findings and the lack of reliability of echographic imaging in providing data which enable us to distinguish a rare neoplastic pattern from the more frequent finding of a benign thyroid mass, fine-needle aspiration (FNA) cytology may today be considered the technique of choice in the screening of the thyroid nodule. Our experience in over 12,000 nodular lesions since 1982, has confirmed that the cytological examination is the most discriminating investigation, diagnostic reliability being far greater than that of traditional techniques. Considering the high frequency of thyroid nodule disease which rarely harbours a carcinomatous lesion, a very scrupulous diagnostic algorithm is mandatory. The FNA cytology, together with morphofunctional and immunological examinations, as well as dynamic exploration of the thyroid hypothalamo-pituitary axis, which allows a nosographic picture of the thyroid nodule disease, provides a more discriminating appraisal for the surgical approach to a single, solitary or prominent nodule.     

The meaning of equivocal pancreatic cytology in patients thought to have pancreatic cancer

INTRODUCTION: Fine needle aspirations (FNAs) and endoscopic retrograde cholangiopancreatography (ERCP)-guided brushings (BRUSH) are useful tools in the differentiation between malignant and benign disease of the pancreas. Once the decision to obtain a cytologic confirmation of one's clinical suspicion is made, the interpretation of the findings, especially an equivocal or negative cytology finding, can be unclear. This study seeks to evaluate the utility of cytologic studies in the evaluation of a patient with suspected pancreatic malignancy. METHODS: A retrospective review of 224 cytologic reports, including 174 FNAs and 50 BRUSHs, from all pancreatic FNAs and BRUSHs performed between January 1989 and June 1995, was performed. Subsequent confirmation of the cytologic diagnosis was made either by histologic or strict clinical criteria. RESULTS: Forty-three percent of the cytologic reports were read as malignant, all others reported as suspicious, atypical, or negative. All cytology studies read as malignant and all FNAs reported as suspicious were histologically or clinically confirmed to be malignant. Of those reported as atypical or negative, 55% and 49% were confirmed to be malignant. Both FNA and BRUSH were 100% specific, 75% sensitive, and 80% accurate. CONCLUSIONS: We conclude that a cytological diagnosis of malignant or suspicious is reliable and useful for further therapy planning in the patient suspected to have a pancreatic malignancy. The reason for the cytologic tests was a strong clinical suspicion, therefore, a high incidence of cancer was found in the patients with atypical or negative readings. A diagnosis of atypical or negative is equivocal and requires further diagnostic maneuvers, frequently including surgery, to make the definitive diagnosis.     

Cystic thyroid lesions in children

BACKGROUND/PURPOSE: Cystic lesions of the thyroid encompass a wide and heterogeneous group of disease states in children, ranging from benign purely cystic entities to malignant tumors. The purpose of this study was to study both the presentation and management of cystic thyroid lesions in the pediatric population. METHODS: A retrospective review of all thyroid masses presenting between 1978 and 1996 and found to be purely or partially cystic on ultrasound examination was conducted, looking at presentation, family history, laboratory values, ultrasound scan and radionuclide imaging, and pathological and cytological evaluation. RESULTS: Twenty-four patients (19 girls, 5 boys) aged 6 to 18 years received the diagnosis of cystic lesions of the thyroid. Of these, 23 presented with painless neck masses, 21 were clinically euthyroid, only one had a single abnormal thyroid function test, only two had mildly positive antithyroid antibody test results, and nearly 30% had a positive family history of thyroid disease. Ultrasonography showed pure cysts in five patients and mixed solid cystic lesions in 19 patients. On scintiscan, six lesions were hot, 13 were cold, three showed normal uptake, and two were mixed. Treatment included either observation, aspiration, cyst sclerosis, surgery, or combinations thereof. Pathological and cytological results included follicular adenoma (n = 9), cystic degeneration (n = 6), multinodular goiter (n = 4), carcinoma (n = 2), branchial cleft cyst (n = 1), and undetermined (n = 2). CONCLUSIONS: Thyroid cysts are often thought to represent benign degenerative disease. Our study, which is the first in the literature to specifically address thyroid cysts in children, shows that ultrasound scan is useful in evaluating thyroid masses, whereas laboratory and radionuclide are of less value, and that single lesions of mixed echogeneity are likely to represent neoplasms, a significant percentage of which are malignant.     

Fine needle aspiration cytology in a rural setting

OBJECTIVE: To compare, contrast and analyze the value and limitations of fine needle aspiration (FNA) cytology and core biopsy (CB) in a rural setting. STUDY DESIGN: Retrospective analysis of 100 FNA cytology and 100 CB results of mass lesions from 193 patients matched for age, sex and body organs, and referred for FNA or CB in rural New South Wales, Australia, between September 1990 and May 1996. RESULTS: FNA cytology and CB results from 193 patients were analyzed, based on anatomic location and cytologic criteria. Sites included lung, retroperitoneum, liver, breast, kidney, pancreas and ovary. The FNA group contained 6 inadequate, 14 benign, 3 atypical, 6 suspicious and 71 malignant cases, whereas the CB group had 1 inadequate, 24 benign and 75 malignant conditions. The inadequate samples in both groups were due to technical difficulty in obtaining representative material. The indeterminate (atypical and suspicious) group, which was the main pitfall of FNA, contained 4 low grade carcinomas, 3 low grade non-Hodgkin's lymphomas and 2 fibrocystic breast changes. The benign FNA group comprised 8 cysts, 5 inflammatory/reactive conditions and 1 benign tumor/hamartoma, whereas the benign CB group contained 11 cysts, 9 inflammatory/reactive conditions and 4 benign tumors. CONCLUSION: FNA was comparable to CB at most anatomic sites. CB occasionally offered additional information. This slight advantage was due to the availability of tissue from the first and often the only pass for assessment of architecture and performance of ancillary tests, which obviated the need for further sampling. On-site assessment of the core imprints at the time of the procedure by the highly skilled and experienced interventional cytopathologist was responsible for limiting the number of attempts to one core in most of the instances, therefore minimizing complications. Pathologists are encouraged to become more familiar with the criteria of aspiration cytology, which has proven its validity in the new cost-conscious environment. Despite the recent surge in the popularity of core biopsy, FNA cytology, when practiced in a multidisciplinary setting, with involvement of pathologists, radiologists and clinicians, is an extremely accurate test with very high sensitivity, which approaches that of surgical pathology, and specificity very similar to that of frozen section. FNA has a positive predictive value for a malignant diagnosis of almost 100%. FNA is a well-tolerated, relatively noninvasive test with a very low risk of complications.     

Ki-ras mutations and the carcinoembryonic antigen level in fine needle aspirates of the pancreas

OBJECTIVE: To evaluate the sensitivity and specificity of the carcinoembryonic antigen (CEA) immunoassay and Ki-ras genotyping as adjuncts to the cytologic diagnosis of pancreatic fine needle aspirates (FNAs). STUDY DESIGN: A retrospective study of 30 patients with pancreatic masses evaluated with CEA immunoassay and gel or hybridization analysis of allele-specific polymerase chain reaction for mutant Ki-ras (codons 12 and 13). DNA was isolated from fixed, paraffin-embedded samples. Diagnoses were correlated with cytologic evaluations and patient outcome. RESULTS: Diagnoses included 17 pancreatic carcinomas, 3 other malignancies and 10 benign lesions. Sixty-five percent of all FNAs had mutated Ki-ras, and 42% of samples with altered Ki-ras had multiple mutations. Replicate FNA samplings in five of six patients had concordant genotypes. Sensitivities for diagnosis were as follows: cytology alone, 76%; CEA alone, 82%; Ki-ras alone, 82%; cytology plus CEA, 100%; cytology plus Ki-ras, 94%. Although specificities for Ki-ras (30%) and CEA (50%) individually were low, elevated CEA level and mutated Ki-ras in a sample with negative cytology strongly indicated false negative cytology. CONCLUSION: The addition of either or both the CEA assay and Ki-ras mutation analysis enhances the sensitivity of the cytologic diagnosis of pancreatic carcinoma by FNA.     

Utility of fine-needle aspiration cytology and frozen-section examination in the operative management of thyroid nodules

Fine-needle aspiration cytology has a high sensitivity for the diagnosis of solitary thyroid nodules. Certain diagnoses involving follicular histologies often cannot be made with needle biopsy alone. The utility of frozen-section examination of thyroid nodules, with particular regard to those lesions with follicular histologies, is also limited. We examined the correlation of fine-needle aspiration cytology and frozen-section examination in solitary thyroid nodules to determine the contribution of frozen-section examination to the operation. We reviewed the fine-needle aspiration cytology, frozen-section examination, and final pathology of 100 consecutive patients undergoing thyroidectomy for a solitary solid thyroid nodule in an 4-year period. The diagnoses were classified as indeterminant, benign, or malignant. The utility and impact of the diagnosis from fine-needle aspiration or frozen section on the operative procedure performed was analyzed. Fine-needle aspiration cytology as a diagnostic test for thyroid nodules demonstrated an indeterminant rate of 23 per cent, with a diagnostic accuracy of 77 and 92 per cent for benign and malignant disease, respectively. In all patients with inaccurate benign diagnosis on fine-needle aspiration cytology, follicular neoplasm was misinterpreted for follicular adenoma or multinodular goiter. In comparing frozen-section results, the indeterminant, benign, and malignant rates were 7, 96, and 64 per cent, respectively. Of the 23 patients with indeterminant results on fine-needle aspiration cytology, the intraoperative frozen-section diagnosis on 4 patients was deferred to permanent section; 18 received accurate cytological diagnosis; and in 1 patient, carcinoma was missed. Overall, the decision about the extent of surgical thyroid resection was changed in only 2 patients based on the frozen-section results. Preoperative evaluation with fine-needle aspiration cytology can accurately and appropriately define the extent of thyroid surgery in most patients with a diagnosis of malignant neoplasm or benign disease. Intraoperative frozen-section examination may be helpful if fine-needle aspiration cytology results are inderminant and in cases of follicular histology as an adjunct for evaluation of the thyroid nodule, but overall, frozen section does not contribute to the management of the thyroid lesion at the time of surgery.     

Cytomorphologic features of fine-needle aspiration of liposarcoma

The cytomorphologic features of fine-needle aspirates (FNA) of liposarcomas have not been fully characterized. In the current study, we attempted to identify cytological attributes of liposarcoma in FNA. Twelve FNAs of histologically proven liposarcomas were used for this study. They included 10 myxoid and two well-differentiated liposarcomas. Four cytological criteria were chosen for evaluation. These included a complex capillary network, increased cellularity, the presence of a metachromatic stroma for myxoid liposarcoma, and finally the identification of lipoblasts. Eighteen FNAs of lipomas and 17 FNAs of nonlipomatous soft-tissue sarcomas were used as controls for evaluation of the same features. The diagnosis of liposarcoma had been rendered on FNA in 7 cases (58%). The diagnosis was suggested in 3 cases (25%), and a suggestion of sarcoma was rendered in 2 cases. Complex capillary networks were identified in 9 of 12 cases (75%); this was seen in 8 of the 10 myxoid liposarcomas and 1 of the 2 well-differentiated neoplasms. Increased cellularity was seen in 7 of 12 cases (58%), metachromatic stroma was seen in 3 of 12 cases (25%), and lipoblasts were identified in 4 of 12 cases (33%). None of the lipomas or sarcomas exhibited a complex capillary network. When capillaries were identified in lipomas, they were straight, with minimal branching. The lipomas did not show evidence of increased cellularity in any cases. Metachromatic stroma was more frequently seen in the nonlipomatous sarcomas than in the liposarcomas. No lipoblasts were identified in any of the control FNAs.     

Isolated thyroid nodule. Comparative value of cyto-puncture and scintigraphy

OBJECTIVES: Nodular thyroid disease, indicated by the presence of single or multiple nodules within the thyroid gland is a common clinical problem, the main question remains the malignancy. Radionuclide scanning, ultrasonography and fine needle aspiration biopsy have been helpful to distinguish benign from malignant nodules and to select patients for surgery. METHODS: We performed a prospective study to assess the comparative value of fine needle nonaspiration biopsy and thyroid scinti scan in the management of 412 patients operated for solitary thyroid nodule. RESULTS: Sensitivity and negative predictive values were the same for both methods, but specificity of cytology was greater than that of thyroid scinti scan (80.53% vs. 10.47%, p < 0.001). DISCUSSION: Thyroid radionuclide scanning remains valuable in the evaluation of a cytological benign solitary thyroid nodule when TSH value is low, in order to distinguish toxic adenoma from cold nodule in Graves' disease.     

Diagnosis from thyroid aspirates. Is the cytopathologist handicapped if not fully informed about the patient?

OBJECTIVE: When fine needle aspiration cytology (FNA) of the thyroid is performed as a first-line test, the cytopathologist cannot be fully informed about the patient's data. The authors investigated whether this decreases the accuracy of FNA and results in consequences for the patient. STUDY DESIGN: FNA smears of 202 patients, 190 with benign and 12 with malignant thyroid disease, were reevaluated, supplying the cytopathologist first with only information from the case history known already at the initial admission, and subsequently with full data. RESULTS: The FNA diagnoses were corrected in 13 cases; in 8/13 they showed a more serious finding. The therapeutic modality was changed in only one case. No corrections were made in the ultimately malignant cases. CONCLUSION: In several cases the cytopathologist may be handicapped by receiving only partial information about the patient, but in our patients this had no demonstrable adverse consequences. Thus, FNA can be performed upon patient's admission.     

Possible relation of osteopontin to development of psammoma bodies in human papillary thyroid cancer

Fine-needle aspiration cytology (FNAC) is the most useful procedure for the evaluation of thyroid nodules. The requirement for repeated aspirations in the follow-up of benign nodular thyroid disease, however, is controversial. To determine the value of re-aspirations in benign nodular thyroid disease, we studied 457 fine-needle reaspirations performed on 216 patients (197 female, 19 male) aged 42.9+/-12 years with uninodular (n = 65) and multinodular (n = 151) thyroid disease. Two hundred fifty-seven of these were second, 137 were third, 46 were fourth, and 17 were fifth re-aspirations of the same nodule, performed in a mean follow-up time of 43.9+/-31 (3-156) months. FNAC results were benign in 407 (89%), insufficient for diagnosis in 31 (6.8%), suspicious in 16 (3.5%), and papillary carcinoma (PC) in 3 (0.7%). An initial benign diagnosis did not change after multiple aspirations in 213 (98.61%) of the cases. Three patients with initial aspirations read as benign had a diagnosis of PC from their second biopsies, (diagnosis confirmed at surgery). Re-examination of the initial FNAC revealed atypical features in 1 of the 3 patients. These 3 patients likely represent a false-negative result of the initial FNAC rather than benign nodular disease transformed to a malignant one during the follow-up period. In conclusion, a second aspiration of clinically suspicious nodules may correct a few initial false-negative results, but routine additional re-aspirations are not useful for clinically stable disease.     

Telomerase activity in lesions of the thyroid: application to diagnosis of clinical samples including fine-needle aspirates

The telomerase enzyme is capable of replacing telomeric DNA sequences that are lost at each cell division. It has been suggested that the function of this enzyme is necessary for cells to become immortal, and in concordance with this hypothesis, telomerase activity has been detected in malignant tumor cells, whereas the enzyme is inactive in normal somatic cells. The measurement of this activity in human tissue samples may have diagnostic value, and in this study, we examined whether such a measurement may be useful for the detection of malignant cells within the thyroid. Telomerase activity was assayed using the telomeric repeat amplification protocol and related to the histological diagnosis of thyroid biopsy tissue samples and of cells obtained from the thyroid by fine-needle aspiration (FNA). Extracts from 9 of 11 (82%) carcinoma biopsy tissue samples contained telomerase activity, whereas enzyme activity was detected in only 2 of 14 (14%) benign tissue sample extracts. These two positive cases were subsequently diagnosed as Graves' disease with severe lymphocytic infiltration. Five of six (83.3%) histologically confirmed carcinoma FNA samples were identified by using the telomeric repeat amplification protocol assay, and two samples considered to be suspicious by FNA cytology were also positive. Conversely, only 4 of 48 (8.3%) benign FNA samples had telomerase. These promising data indicate that this sensitive assay could become a useful adjunct to microscopic cytopathology in the detection of cancer cells in small tissue biopsies and in fine-needle aspirates of the thyroid.     

Usefulness of color echo Doppler with power Doppler in the diagnosis of hypoechoic thyroid nodules: work in progress

The aim of this study was twofold: first, to improve the predictive value of ultrasonography (US) in differentiating benign from malignant thyroid nodules and, second, to investigate whether color Doppler and power Doppler can distinguish different morpho-hemodynamic patterns of hypoechoic thyroid nodules according to their vascularity. Twenty-nine patients with hypoechoic thyroid nodule(s) were entered into this work in progress. Three typical power Doppler patterns were recorded and compared with color Doppler patterns and with cytologic and/or histologic findings. Power Doppler patterns were classified as follows: type A, a perilesional vascular halo; type B, a peri- and intralesional vascular halo, subdivided into: 1) with moderate intralesional vascularization, homogeneous structure and regular vessel caliber and 2) with rich intralesional vascularization, anarchical structure and winding vessel caliber and flow; type C, a perilesional vascular halo with a characteristic peripheral large afferent vessel characterized by winding caliber and flow. Of 29 patients, 21 had type A power Doppler (benign nodular goiter at cytology, in 4 of them with regressive phenomena); seven patients had type B power Doppler patterns-4 had a subtype 1 pattern (3 with nodular hyperplasias and 1 with a papillary adenoma), 3 had a subtype 2 (two had a follicular adenoma and one had a final diagnosis of angioinvasive follicular carcinoma). The patient with undifferentiated carcinoma had a type C power Doppler pattern. In conclusion, according to our early results, PD seems to be more sensitive and reliable than CD in the screening of thyroid nodules, and to yield better vascular information.     

Significance of nondiagnostic fine-needle aspiration of the thyroid

BACKGROUND: Fine-needle aspiration biopsy (FNAB) has been shown to be rapid and cost effective in the evaluation of thyroid nodules. The significance of nondiagnostic (unsatisfactory) FNAB is uncertain, however. METHODS: We reviewed 345 consecutive thyroid FNABs and identified 59 patients with initially unsatisfactory specimens. These patients had follow-up to determine whether their thyroid nodules proved to be malignant. RESULTS: Three patients (5.1%) were found to have organ-confined papillary carcinoma of the thyroid, the largest tumor mass measuring 1.2 cm. Six patients (10.2%) had benign adenomas. CONCLUSIONS: In most cases of initially nondiagnostic FNAB of a thyroid nodule, neoplasia is not found subsequently. A minority of cases may still harbor malignancy. None of our patients in whom repeated FNA was either nondiagnostic or suggestive of benign disease were ultimately found to have a malignancy.     

Aberrant tau phosphorylation and neurite retraction during NGF deprivation in PC12 cells

OBJECTIVE: To investigate the final results of cases with preoperative diagnoses of thyroid follicular neoplasms by fine needle aspiration cytology (FNAC). STUDY DESIGN: A retrospective review of 6,499 patients who received thyroid ultrasonography with FNAC at Chang Gung Memorial Hospital. Among 6,499 patients, 209 (3.2%) were diagnosed by FNAC as having follicular neoplasms, of which 84 received surgical treatment. Eighty-two of the 84 cases had a frozen section prepared during the operation. RESULTS: Thyroid malignancy was confirmed histopathologically in 164 cases. Among 84 thyroid follicular neoplasm patients, 21 cases were diagnosed as malignant tumors, including papillary thyroid carcinoma, follicular thyroid carcinoma, medullary thyroid carcinoma and Hürthle's cell carcinoma. Ultrasonography on these 21 patients revealed that 16 cases (76.2%) had low echo density in the thyroid nodule. The percentage was statistically significantly different from that in benign cases, 23.8% (P < .05). A higher incidence of malignancy was found in males, but the data did not reach statistical significance (P = .0586). CONCLUSION: Most of the follicular neoplasms revealed by FNAC were benign lesions. Low echo density on ultrasonography and male sex carried a higher risk of malignancy.     

Expression of glutathione-peroxidase (GSH-PO) in the rat ventral prostate--effect of castration and administration of testosterone

This series retrospectively reviewed 3657 patients who received thyroid ultrasonography with fine-needle aspiration cytological (FNAC) examinations at Chang Gung Memorial Hospital during the period from January 1, 1993 to December 31, 1993. Thyroid ultrasonography studies were performed using a real-time ultrasonographic machine with a 10 MHz transducer. The aspirates were air dried and stained by the Romanowsky-based Liu method. Three hundred seventy-eight cases (10.3%) received surgical treatment after the ultrasonographic and FNAC examinations. Benign lesions were diagnosed in 269 patients. Thyroid malignancy was confirmed histopathologically in 109 cases including 76 papillary thyroid carcinomas, 17 follicular carcinomas, 5 medullary thyroid carcinomas, 3 anaplastic carcinomas, 3 Hürthle cell carcinomas, and 3 lymphomas. Another 2 cases were metastatic cancer to thyroid. The results demonstrated that 28.8% of the surgically treated patients had histopathologically proven malignancies. The incidence of thyroid malignancy was 2.98% in this study. The sensitivity of the cytological diagnosis was 79.80% and the specificity was 98.66%. The positive predictive value was 96.34%. Negative predictive value was 91.70%. The false negative index was 20.20%. The diagnostic accuracy was 92.89%. Thyroid ultrasonography with the FNAC can provide high specificity and sensitivity in differentiating malignant lesions from benign.     

Predictive value of fine-needle aspiration of the thyroid in the classification of follicular lesions

BACKGROUND: Fine-needle aspiration has been less valuable in the diagnosis of follicular lesions than for other neoplasms of the thyroid. It has been observed that follicular carcinoma is found in microfollicular, but not macrofollicular lesions, and this has served as a guide to management for many surgeons. The authors attempted to determine what cytologic parameters might usefully distinguish these types of follicular lesion. METHODS: The histologic findings and cytology of 56 thyroid lobectomies for follicular lesions that had adequate preoperative fine-needle aspiration of the thyroid (FNAT) were reviewed. Histologic specimens were classified into macrofollicular, mixed, and microfollicular groups. Cytologic features examined included the presence of colloid, irregularity of cell arrangements within groups, the presence and size of flat and folded cell sheets, three-dimensional clusters, and microfollicles and macrofollicles. RESULTS: Of the histologic specimens, 15 were preponderantly (> 70%) microfollicular, 19 were mixed, and 22 were predominantly (> 70%) macrofollicular. Three cytologic features were useful in their distinction: none of the predominantly microfollicular but 24% of the mixed and predominantly macrofollicular had abundant colloid (P = 0.048). Likewise, none of the predominantly microfollicular but 27% of the mixed and predominantly macrofollicular had large follicles (P = 0.026). Finally, 73% of the predominantly microfollicular but only 37% of the mixed and predominantly macrofollicular showed irregularity or crowding of cells in groups (P = 0.018). CONCLUSIONS: Used in combination, abundant colloid, regular spacing, and large follicles are helpful in distinguishing macrofollicular and mixed lesions from microfollicular ones, which have a higher malignant potential.     

Aspiration cytology of ectopic cervical thymoma mimicking a thyroid mass. A case report

BACKGROUND: Ectopic cervical thymoma, first described in 1941 by Boman, is an uncommon tumor of the neck displaying the same histologic features as mediastinal thymoma. Since it is commonly located in the anterolateral part of the neck or is subjacent to or inside the lower pole of the thyroid, the mass is often confused as being of thyroid origin. CASE: A 68-year-old female presented with dyspnea and an anterior neck mass found on routine chest roentgenography. The thyroid scan showed a cold nodule in the lower pole of the left part of the thyroid. Fine needle aspiration (FNA) cytology revealed large numbers of small lymphocytes with hyperchromatic nuclei and frequent clumping pattern in the pale, eosinophilic, fluid background. A few clusters of epithelial cells without atypism were interpreted as thyroid follicular cells. The overall cytologic features were misinterpreted as malignant lymphoma of the thyroid. However, the histologic diagnosis was thymoma, predominantly cortical type. CONCLUSION: The ectopic cervical thymoma is sometimes misdiagnosed as Hashimoto's thyroiditis, anaplastic carcinoma and malignant lymphoma of thyroid on FNA cytology or frozen diagnosis due to its rarity. Therefore, the differential diagnosis of a neck mass showing a variable composition of lymphocyte and epithelial component in a pale, eosinophilic, fluid background should also include ectopic cervical thymoma, especially in elderly females.