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Yvan C Bedard

Publications and source records attributed to Yvan C Bedard.

6 recordsLinked to original sources
PubMed2005

Fine-needle aspiration biopsy findings suspicious for papillary thyroid carcinoma: a review of cytopathological criteria.

OBJECTIVES/HYPOTHESIS: The objective was to evaluate the usefulness of standard suspect cytological features on fine-needle aspiration biopsy (FNAB) in predicting papillary thyroid carcinoma. STUDY DESIGN: Retrospective chart review of consecutive fine-needle biopsies of the thyroid. METHODS: The study was a retrospective review of consecutive patients presenting with a diagnosis of suspected (group 1) or positive papillary thyroid carcinoma (group 2). The frequency of standard cytological features (i.e., papillary architecture, multinucleated giant cell, nuclear pseudo-inclusions, nuclear grooves, micronucleoli, powdery chromatin, and psammoma bodies) were recorded for each group. These were compared using chi test. Sensitivity and specificity for both individual and a combination of features were calculated for patients in group 1. RESULTS: One hundred eight patients were eligible for the study (group 1, n = 57; group 2, n = 51). Fifty-one patients (89%) in group 1 and all patients in group 2 had a histopathological diagnosis of papillary thyroid carcinoma. Respectively, the most frequent features present on fine-needle aspiration biopsy in group 1 versus group 2 were nuclear grooves (79% vs. 88%), micronucleoli (74% vs. 86%), pseudo-inclusions (58% vs. 88%), and powdery chromatin (47% vs. 59%); P values for these features were P > .05, P > .05, P < .05, and P > .05, respectively. In group 1, the sensitivities of nuclear grooves and micronucleoli were 80% and 71%, respectively. The presence of psammoma bodies was associated with a specificity of 100%. A combination of nuclear grooves, micronucleoli, pseudo-inclusions, powdery chromatin, and multinucleated giant cells was 100% specific in detecting papillary thyroid carcinoma. CONCLUSION: In choosing the most appropriate management of a finding suspect for papillary thyroid carcinoma on fine-needle aspiration biopsy, the surgeon must be aware of the diagnostic importance of certain cytopathological features. The presence of a combination of these factors may allow a more confident surgical approach.

Biopsy, Fine-Needle↗
PubMed2005

Single versus sequential fine-needle aspiration biopsy in the management of thyroid nodular disease.

UNLABELLED: Fine-needle aspiration biopsy (FNAB) is considered a safe, reliable and cost-effective means of selecting thyroid nodules with risk for malignancy. However, there are limitations of this method including false positive/negative and "nondiagnostic" results that may be reduced by repeating FNAB. OBJECTIVE: To evaluate accuracy, sensitivity, specificity and costs of sequential FNAB in the management of thyroid nodular disease. METHODS: Charts of all patients who underwent thyroidectomy at a university teaching hospital in Toronto from 1998 to 2000 were reviewed. FNAB reports of "suspicious for malignancy," "follicular lesion" and "cellular atypia" were considered to be positive. Data were analyzed with chi2 and z tests. RESULTS: There were 268 patients (225 women and 43 men; age range 18-89 yr; mean age 47 yr) who underwent a total of 449 FNABs (mean 1.7 FNABs/patient) within a year before thyroidectomy. Accuracy (63.8%), sensitivity (73.8%) and specificity (69%) were determined for single FNABs. Sequential FNAB increased the accuracy of method by 22.6%, sensitivity by 13.8% and specificity by 6.2%, with reduction of false positive/negative results by 14.2% and "nondiagnostic" results by 100%. However, the costs of sequential cytology per patient were 70% higher than single FNAB. CONCLUSIONS: Multiple FNABs are unpleasant for patients, but useful in the selection for treatment of patients with thyroid nodular diseases. Although sequential FNAB increases the costs of method, the improvement of precision of FNAB may imply a reduction in overall health-care costs.

Adult↗
PubMed2004

Role of fine-needle aspiration biopsy and frozen section in the management of papillary thyroid carcinoma subtypes.

Since fine-needle aspiration biopsy (FNAB) was introduced, the value of frozen section (FS) has been questioned. This study compares FNAB and FS sensitivities among the usual form of papillary thyroid cancer (uPTC) and variants of PTC such as tall cell (tcPTC), follicular (fPTC), and Hurthle cell (HcPTC). A total of 257 patients who underwent preoperative FNAB, intraoperative FS, and thyroidectomy for PTC were, randomly selected from a database of a university teaching hospital in Toronto. There were 218 females (84.8%) and 39 males (15.2%), from 19 to 89 years of age (mean of 44 years), having uPTC (n = 212), fPTC (n = 24), HcPTC (n = 14), and tcPTC (n = 7). Data were analyzed using chi2 test. Sensitivities were calculated by division of true positives and by the sum of true positives and false negatives. True positives had to reflect a conclusive diagnosis of cancer. The FNAB sensitivities were uPTC (39.2%), fPTC (25%), HcPTC (42.9%), tcPTC (85.7%), similar to FS sensitivities (p = 0.497) for uPTC (44.3%), fPTC (16.7%), HcPTC (42.9%), and tcPTC (71.4%). Use of FS following FNAB increased sensitivities for uPTC to 56.1%, fPTC to 29.2%, and tcPTC to 100%. In addition, FS did not increase FNAB sensitivity in HcPTC. Combination FNAB plus FS failed in 43.9% of uPTC, 70.8% of fPTC, and 57.1% of HcPTC. We concluded that FNAB and FS sensitivity vary with PTC subtype and are still necessary for selection and treatment. The recognition of morphologic subtypes of PTC from the FNAB could optimize the selection of patients for intraoperative FS, enhance the preoperative assessment of prognosis, facilitate the surgical planning, and simplify the preparation of postoperative adjuvant therapy.

Adult↗
PubMed2004

Clinicopathologic significance of histologic vascular invasion in papillary and follicular thyroid carcinomas.

BACKGROUND: The association of angioinvasion with tumor aggressiveness in follicular and papillary thyroid carcinoma remains unclear. This study addresses this problem focusing on clinicopathologic relevance of angioinvasion in the treatment of papillary thyroid carcinoma and follicular thyroid carcinoma. METHODS: From a university hospital database, 358 patients with papillary thyroid carcinoma or follicular thyroid carcinoma were randomly selected. Their charts were retrospectively analyzed and divided into papillary thyroid carcinoma and follicular thyroid carcinoma groups. Each group was subdivided into angioinvasive and nonangioinvasive tumor subgroups. All data were analyzed using Student's t-test, Mann-Whitney rank sum test, chi-square test, and Fisher's exact test. RESULTS: There were 289 women and 69 men, ages 18 to 89 years. Papillary thyroid carcinoma (86%) was more frequent than follicular thyroid carcinoma. Most patients had nonangioinvasive tumor (90.2%). After a mean followup of 43.6 months, there were no significant differences between papillary thyroid carcinoma subgroups for local recurrence (p = 0.69), persistent elevated serum thyroglobulin (p = 0.568), and distant metastasis rates (p = 0.422). No death related to the cancer was observed in both papillary thyroid carcinoma subgroups (p = 1), except for one death resulting from a concomitant nasopharyngeal cancer. The longterm prognosis was less favorable for angioinvasive papillary thyroid carcinoma based on AJCC (American Joint Committee on Cancer staging), AMES (age, distant metastasis, tumor extent, and size), and MACIS (distant metastasis, age, completeness of primary tumor resection, local invasion, and tumor size), but the angioinvasive papillary thyroid carcinoma were larger than nonangioinvasive papillary thyroid carcinomas. The short-term clinical outcomes in both follicular thyroid carcinoma, after a mean followup of 72.3 months, were comparable in terms of local recurrence (p = 0.34), persistent elevated serum thyroglobulin (p = 1), and distant metastasis (p = 0.597). There was no death related to cancer in both follicular thyroid carcinoma subgroups (p = 1). There were no significant differences between both follicular thyroid carcinoma subgroups for longterm prognosis. CONCLUSIONS: Our results indicate that angioinvasion does not adversely influence short-term outcomes or longterm prognosis in follicular thyroid carcinoma and short-term outcomes in papillary thyroid carcinoma. Angioinvasion is a postoperative pathologic finding that does not justify an ominous prognosis or drastic therapeutic measures.

Adenocarcinoma, Follicular↗
PubMed2004

Thyroid colloid nodules diagnosed by fine-needle aspiration: efficacy of suppression.

BACKGROUND: This study reviewed the accuracy of fine-needle aspiration biopsy (FNAB) and the efficacy of thyroid suppression for colloid nodules in our population to determine the utility of these two modalities on the decision to operate. METHODS AND MATERIALS: A retrospective chart review of patients with colloid nodules diagnosed by FNAB from January 1993 to July 1995 was conducted. A 52-patient cohort underwent surgical management, and their needle aspirate cytologies and final pathologies were reviewed. RESULTS: A 7.7% false-negative rate in the detection of thyroid malignancy by FNAB was obtained. This is in keeping with data reported in the literature. Virtually no efficacy of hormonal suppression in our population was found. CONCLUSION: When the literature is reviewed and compared with the results of this study, the use of FNAB as a decision tool to operate is valid. The decision to operate based on the outcome of hormonal suppression, however, is not valid based on our results.

Biopsy, Needle↗