Fine-needle aspiration biopsy of the thyroid in an area of endemic goitre: influence of restored sufficient iodine supplementation on the clinical significance of cytological results.
(9/100)
OBJECTIVE: The iodine status of the population of Poland has markedly improved over the past years. The aims of this paper were: (i) to examine the diagnostic value of fine-needle aspiration biopsy (FNAB) of the thyroid in goitre endemic regions (in conditions of improved iodine supply), and (ii) to find whether the changes in iodine supply have already influenced the clinical interpretation of cytological results. METHODS: Cytological diagnoses, based on 3782 aspirates, obtained from 3572 patients during the years 1985-1999, were verified by reference to the results of postoperative examinations. The relative occurrences of selected cytological results in 1992-1999 were also compared (patients not subjected to surgery were included). RESULTS: We have found that the frequency of neoplastic lesions significantly decreased throughout the examined period (P<0.02). The ratio of the papillary carcinoma frequency to the follicular carcinoma frequency increased from 1.7 during 1992-1993 up to 8.0 during 1998-1999 (P<0.05). The frequency of cytologically diagnosed chronic thyroiditis increased from 1.5% in 1992 to 5.7% in 1999 (P<0.001); the percentage of cytological diagnosis of "follicular neoplasm" decreased during the same time (P<0.001). The risk of malignancy significantly lowered in the cytological diagnoses of "follicular neoplasm" from 15% during 1985-1993 to 6% during 1996-1999 (P<0.05). CONCLUSIONS: The diagnostic value of FNAB during the period without proper iodine prophylaxis did not differ significantly from that during the last examined period. However, the changes in iodine supply have markedly and promptly affected the clinical significance of particular cytological results. (+info)
Follicular-patterned lesions of the thyroid: the bane of the pathologist.
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This review focuses on follicular-patterned lesions of the thyroid gland and their differential diagnosis. Included are a discussion of the features differentiating follicular adenoma from adenomatous or hyperplastic nodule and follicular adenoma from follicular carcinoma and the follicular variant of papillary thyroid carcinoma. The cytologic and histologic characteristics are described, and criteria for diagnosing the major follicular lesions are reviewed. (+info)
Prognosis for fertility and ovarian function after treatment with radioiodine for thyroid cancer.
(11/100)
The aim of this study was to review the outcome of ablative radioiodine treatment on ovarian function in young women treated for differentiated thyroid carcinoma. Of 1398 patients with differentiated thyroid cancer, 496 were women under the age of 40 at the time of diagnosis who had received radioiodine therapy. Of these, 322 received a single 3 GBq ablation dose of radioiodine while the remainder received subsequent treatment with (131)I with a cumulative activity of 8.5-59 GBq for residual, recurrent, or metastatic disease. Transient amenorrhoea or menstrual irregularities lasting up to 10 months were experienced in 83 patients (17%). No cases of permanent ovarian failure were recorded. There were 427 children born to 276 women; only one patient wishing to achieve a successful pregnancy outcome has been unsuccessful. Four premature births and 14 miscarriages occurred but no congenital abnormalities were reported. The risk of permanent damage to the ovaries after ablative radioiodine treatment appears to be low and patients can be reassured they can have normal pregnancies after this treatment. (+info)
Implications of follicular neoplasms, atypia, and lesions suspicious for malignancy diagnosed by fine-needle aspiration of thyroid nodules.
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OBJECTIVE: To break out subcategories of atypical and suspicious cytologic interpretations of thyroid aspirations and correlate those with final histologic diagnosis. SUMMARY BACKGROUND DATA: Fine-needle aspiration (FNA) of thyroid nodules has become the primary diagnostic tool in the initial evaluation of thyroid nodules. Management of thyroid nodules is based on statistical data correlating a specific cytologic reading with the probability of malignancy. Two particular cytologic readings that frustrate both cytopathologists and surgeons are follicular neoplasms and cells that show atypia. In most reported series, follicular neoplasms and cells showing atypia are included in a broad "suspicious" category, with reported overall malignancy rates generally between 20% and 30%. However, there is interest in determining whether these suspicious lesions can be subcategorized, allowing a more accurate assessment of the risk of malignancy. In addition, there is recent evidence that the incidence of follicular cancer may be declining in this country, possibly decreasing the probability that a "follicular neoplasm" will prove to be a follicular cancer. METHODS: From January 1994 through December 2000, 709 thyroid FNAs were performed at a single institution. Those interpreted as suspicious and the subsequent histologic reports were reviewed. From this set, four specific categories were defined, and the clinical records for patients whose cytology matched these categories form the subject of this study. These four categories are follicular neoplasms without atypia, follicular neoplasms with atypia, atypia, and suspicious for malignancy. In addition, lesions with nondiagnostic cytology were reviewed. Only lesions for which there was histologic follow-up were considered. RESULTS: Ninety-eight aspirates were categorized as follicular neoplasms without atypia, follicular neoplasms with atypia, or atypia alone. Of 74 follicular neoplasms without atypia, only 5 (6.8%) were malignant, and none of these were follicular thyroid cancers. Nine of the lesions were follicular neoplasms with atypia, and four (44.4%) of these were malignant, including two that were invasive follicular cancers. Of 15 lesions showing atypia alone, 3 (20%) were malignant, all of which were papillary thyroid cancers. Twenty-five additional patients had lesions highly suspicious for malignancy. Twenty-one (84%) of these lesions were malignant, the majority being papillary thyroid cancers. Only one was a follicular cancer. Fifty patients with nondiagnostic cytology had subsequent action taken. Thirty-one of these lesions were resected, with five (16.1%) proving to be malignant. CONCLUSIONS: Thyroid nodules whose FNA is diagnosed as highly suspicious for malignancy should be resected unless there are significant contraindications to a surgical procedure. The extremely low rate (2%) of invasive follicular cancers among all follicular neoplasms may reflect changing histologic criteria for follicular carcinoma, a true change in the disease frequency, or both. For thyroid nodules whose cytology shows a follicular neoplasm without atypia, malignancy rates of 8% or less may allow nonsurgical options, including reevaluation in selected populations. Continued efforts to correlate malignancy rates to specific cytologic criteria will allow patients to make more informed decisions regarding their medical care. (+info)
The null genotype of glutathione s-transferase M1 and T1 locus increases the risk for thyroid cancer.
(13/100)
Susceptibility to chemical carcinogens plays an important role in the development of most cancers. Several polymorphisms of human drug-metabolizing enzymes influence this individual susceptibility. The genes that encode the isoenzymes of the glutathione s-transferase (GST) system present a polymorphic inheritance. The GST mu 1 (GSTM1) and GST theta 1 (GSTT1) genes have a null allele variant in which the entire gene is absent. The null genotype for both enzymes has been associated with many different types of tumors. To look for the influence of the inheritance pattern of these enzymes on thyroid cancer risk, we used a triplex PCR that included beta-globin gene as a DNA quality control to compare 300 normal individuals of our population to 116 goiter patients. There were 49 cases of benign and 67 cases of malignant nodules: 50 papillary and 17 follicular carcinomas. Comparison between thyroid tumor specimens and normal corresponding samples of 35 cancer patients demonstrated identical patterns, suggesting that the GST system is not involved in the process of follicular dedifferentiation. There was no statistical difference between the prevalence of the deleted alleles in the normal individuals and in the goiter patients. However, papillary carcinoma patients (10%) and follicular carcinoma patients (17%) presented a higher prevalence of the null genotype than the normal population individuals (5%; P < 0.05). We found a 2.6 increased risk of thyroid cancer in individuals with the GSTT1 and GSTM1 combined null inheritance, suggesting that this genotype may be associated with an increased susceptibility to thyroid cancer. (+info)
Increased expression of AP2 and Sp1 transcription factors in human thyroid tumors: a role in NIS expression regulation?
(14/100)
BACKGROUND: Sodium/iodide symporter (NIS) is a key protein in iodide transport by thyroid cells and this activity is a prerequisite for effective radioiodide treatment of thyroid cancer. In the majority of thyroid cancers, however, iodide uptake is reduced, probably as a result of decreased NIS protein expression. METHODS: To identify the mechanisms that negatively affect NIS expression in thyroid tumors, we performed electrophoresis mobility shift assays and immunoblot analysis of nuclear protein extracts from normal and tumoral thyroid tissues from 14 unrelated patients. RESULTS: Two proteins closely related to the transcription factors AP2 and Sp1 were identified in the nuclear extracts. Expression of both AP2 and Sp1 in nuclear extracts from thyroid tumors was significantly higher than that observed in corresponding normal tissues. CONCLUSION: These observations raise the possibility that NIS expression, and subsequently iodide transport, are reduced in thyroid tumors at least in part owing to alterations in the binding activity of AP2 and Sp1 transcription factors to NIS promoter. (+info)
Serum thyroglobulin and 131I whole body scan after recombinant human TSH stimulation in the follow-up of low-risk patients with differentiated thyroid cancer.
(15/100)
OBJECTIVE: The 'standard' postoperative follow-up of patients with differentiated thyroid cancer (DTC) has been based upon serum thyroglobulin (Tg) measurement and (131)I whole body scan ((131)I-WBS) after thyroid hormone (T(4)) treatment withdrawal. However, (131)I-WBS sensitivity has been reported to be low. Thyroid hormone withdrawal, often associated with hypothyroidism-related side effects, may now be replaced by recombinant human thyroid stimulating hormone (rhTSH). The aim of our study was to evaluate the diagnostic accuracy of (131)I-WBS and serum Tg measurement obtained after rhTSH stimulation and of neck ultrasonography in the first follow-up of DTC patients. DESIGN: Ninety-nine consecutive patients previously treated with total thyroidectomy and (131)I ablation, with no uptake outside the thyroid bed on the post-ablative (131)I-WBS (low-risk patients) were enrolled. METHODS: Measurement of serum Tg and (131)I-WBS after rhTSH stimulation, and ultrasound examination (US) of the neck. RESULTS: rhTSH-stimulated Tg was 1 ng/ml (Tg+) in 21 patients, including 6 patients with Tg levels >5 ng/ml. (131)I-WBS was negative for persistent or recurrent disease in all patients (i.e. sensitivity = 0%). US identified lymph-node metastases (confirmed at surgery) in 4/6 (67%) patients with stimulated Tg levels >5 ng/ml, in 2/15 (13%) with Tg >1<5 ng/ml, and in 2/78 (3%) who were Tg-negative. CONCLUSIONS: (i) diagnostic (131)I-WBS performed after rhTSH stimulation is useless in the first follow-up of DTC patients; (ii) US may identify lymph node metastases even in patients with low or undetectable serum Tg levels. (+info)
Pure versus follicular variant of papillary thyroid carcinoma: clinical features, prognostic factors, treatment, and survival.
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BACKGROUND: The follicular variant of papillary thyroid carcinoma (FVPTC) is a common subtype of papillary thyroid carcinoma. Few studies have compared the clinical behavior and treatment outcome of patients with FVPTC with the outcome of patients with pure papillary carcinoma (PTC). A retrospective study was performed to identify the influence of FVPTC compared with PTC on therapeutic variables, prognostic variables, and survival. METHODS: A clinicopathologic analysis of 243 patients with papillary carcinoma was performed. One hundred forty-three tumors were PTC, and 100 tumors were FVPTC. The following variables were evaluated: age at diagnosis, tumor size, stage of tumor, treatment, capsular invasion, and survival. RESULTS: The median follow-up was 11.5 years. The median age was 43 years in the PTC group and 44 years in the FVPTC group. The median tumor size, disease stage, and type of initial surgery and iodine 131 ablation were similar. More patients had capsular invasion by the tumor and less metastases to cervical lymph nodes in the FVPTC group. The actuarial survival of patients age < 40 years was higher compared with the survival of patients age > 50 years in both groups. The 21-year overall actuarial survival was 82% in patients with PTC and 86% in patients with FVPTC (P value not significant). CONCLUSIONS: The pathologic and clinical behaviors of PTC and FVPTC were comparable. Prognostic factors, treatment, and survival also were similar. Patients in both groups must be treated identically. (+info)