Accuracy of fine needle aspiration cytology and frozen section histopathology for lesions of the major salivary glands.

INTRODUCTION: Identifying malignancy either preoperatively or intraoperatively can have a significant impact on the management of salivary gland tumours. We review our experience with fine needle aspiration cytology (FNAC) and frozen section (FS) for salivary gland lesions. We analyse the accuracy of both modalities and their influence on management. MATERIALS AND METHODS: Retrospective review of 114 patients who underwent salivary gland surgery, 91 with intraoperative FS and 68 with preoperative FNAC. Both sets of results were compared against each other and the final histopathological diagnosis. RESULTS: The accuracy of FS was 92.3%, with a sensitivity and specificity of 62.5% and 100%. Histologic concordance was 92.4% for benign lesions, and 100% for malignant tumours. The accuracy of FNAC was 89.7%, with a sensitivity and specificity of 100%. The non-diagnostic rate was 10.3%. Histologic concordance for FNAC was inferior to that for FS, with only 64.2% of benign lesions and 50% of malignant tumours correctly identified. FNAC did not alter the management of benign disease even when a correct diagnosis was obtained. CONCLUSION: Our results suggest that FNAC and FS are complementary in usefulness for malignant tumours. However, FNAC does not influence the management of benign lesions and routine FNAC for every patient may not be cost-effective.

Transcervical superior mediastinal lymphadenectomy in the management of papillary thyroid carcinoma.

AIM: Surgery is the treatment of choice for lymph node metastases in papillary thyroid carcinoma. When adequately treated by surgical extirpation, the presence of lymph node involvement does not seem to have a negative impact on cure rates or survival. Surgical lymphadenectomy for metastatic papillary thyroid carcinoma has been well described for both the central and the lateral compartments of the neck. Superior mediastinal lymphadenectomy, however, has only sporadically been mentioned. We describe our experience with transcervical superior mediastinal lymphadenectomy (TSML) that avoids the morbidity of the traditional sternal split. MATERIALS AND METHODS: This retrospective analysis included 30 patients (24 women and 6 men; age range, 17-72 years) who underwent TSML by the senior author (JLF) for papillary carcinoma metastatic to the superior mediastinum between 1985 and 1999. Histopathologic examination confirmed positive nodes in all the mediastinal dissections. All patients received postoperative I(131). RESULTS: All the patients are alive after a median follow-up of 5 years (range, 1-14 years). Twenty-nine of 30 patients remain free of disease, whereas one patient is alive with lung and bone metastases. No patient has had local or regional relapse. The only significant complication was a high incidence of temporary (70%) and later permanent (50%) hypoparathyroidism. CONCLUSIONS: TSML is a safe and effective treatment for superior mediastinal metastases in papillary thyroid carcinoma.

Thyroid calcification and its association with thyroid carcinoma.

AIM: Calcification within the thyroid gland may occur in both benign and malignant thyroid disease, and its detection on ultrasonography is frequently dismissed by many clinicians as an incidental finding of little significance. As a tertiary referral center, most of our thyroid patients will have had thyroid ultrasonography before being referred to us, and in our experience, the incidence of malignancy in a thyroid nodule containing calcification seems to be higher than that in the average thyroid nodule. To assess this risk, we conducted this retrospective review. MATERIALS AND METHODS: Our analysis included 462 consecutive patients who underwent thyroid surgery at our institution between 1995 and 1999. We reviewed all the patients' charts for data regarding clinical findings, preoperative diagnostic investigations, and histopathologic diagnosis. Of the 462 patients, 361 (78.1%) had thyroid ultrasonography before surgery, and 49 (13.6%) of these ultrasounds showed intrathyroidal calcification. RESULTS: Of the 49 patients whose ultrasounds showed intrathyroidal calcification, 29 (59.2%) were found on histopathologic examination to have thyroid carcinoma. Twelve of the remaining 20 patients had multinodular goiters. Of the 29 patients with malignancy, seven (24.1%) had preoperative fine-needle aspirates that were reported as benign. After excluding patients who were initially seen with multinodular disease, in the subset of 37 patients who presented with a solitary thyroid lesion with calcification, 28 (75.7%) were found to have carcinoma. CONCLUSIONS: When calcification is noted within a solitary thyroid nodule, the risk of malignancy is very high. Surgery should be recommended regardless of the result of fine-needle aspiration cytologic findings.

Cyclin D1 protein expression predicts metastatic behavior in thyroid papillary microcarcinomas but is not associated with gene amplification.

Overexpression of cyclin D1 occurs in several malignancies, often due to gene amplification, and this has been associated with aggressive tumor behavior, a higher incidence of lymph node metastases, and a poorer prognosis. The role of cyclin D1 in the pathogenesis of thyroid malignancy is unknown; however, cyclin D1 expression has been reported to occur in a proportion of well differentiated thyroid carcinomas. Micropapillary carcinomas of the thyroid are common incidental findings that almost always behave in an indolent manner and remain quiescent. However, rare microcarcinomas behave aggressively and metastasize early, giving rise to clinically significant disease. We hypothesized that cyclin D1 might play a role in the aggressive behavior of metastasizing papillary microcarcinomas. We reviewed the histopathology reports of 2,000 patients who underwent thyroid surgery at our institution between 1995-1999 and identified 22 patients who presented with gross regional metastases from a primary papillary microcarcinoma. These patients formed the index cohort for this analysis. As controls, we selected 34 patients with nonmetastasizing microcarcinomas. We studied these tumors for immunoreactivity to cyclin D1 on immunohistochemistry and analyzed 13 tumors that diffusely expressed cyclin D1 for gene amplification by differential PCR. Twenty of the 22 (90.9%) metastasizing papillary microcarcinomas expressed cyclin D1, compared with 3 of the 34 (8.8%) nonmetastasizing papillary microcarcinomas (P < 0.001). However, of the 13 tumors that showed diffuse immunoreactivity for cyclin D1 on immunohistochemistry, none showed amplification of the cyclin D1 gene on differential PCR. We conclude that cyclin D1 is significantly overexpressed in metastasizing papillary microcarcinomas of the thyroid. This is likely due to mechanisms other than gene amplification. Cyclin D1 immunohistochemistry may be a valuable tool in predicting metastatic potential in papillary microcarcinomas.

Overexpression of cyclin D1 and underexpression of p27 predict lymph node metastases in papillary thyroid carcinoma.

Lymph node metastasis in papillary thyroid carcinoma increases the morbidity of treatment and the risk of local regional relapse and may also affect cure rates and survival. Factors that predict lymph node metastasis are, however, unclear. We analyzed 125 patients with papillary thyroid carcinoma for factors that predict lymph node metastasis. On univariate analysis, age, extrathyroidal extension, tumor focality, overexpression of cyclin D1, and underexpression of p27 predicted lymph node metastasis, whereas patient gender and tumor size did not. On multivariate analysis, extrathyroidal extension, overexpression of cyclin D1, and underexpression of p27 proved to be strong independent predictors of lymph node metastasis. We suggest that immunohistochemistry for cyclin D1 and p27 will prove valuable in identifying papillary thyroid carcinomas with metastatic potential.

Underexpression of p27/Kip in thyroid papillary microcarcinomas with gross metastatic disease.

OBJECTIVE: Papillary microcarcinomas (PMCs) of the thyroid (measuring less than 1 cm in maximum dimension) are extremely common incidental histologic findings, and most of these tumors are not considered clinically significant. However, rare PMCs behave aggressively and metastasize early, giving rise to clinically significant metastatic disease. We hypothesized that p27 and MIB-1/Ki-67 immunoreactivity would allow us to identify this small subgroup of PMCs that have the potential to behave aggressively. METHODS: We reviewed the histopathology reports of 2000 patients who underwent thyroid surgery at our institution between 1995 and 1999 and identified 22 patients who presented with gross regional metastases from a primary PMC. The primary and metastatic tumors were stained for ret, p53, p27, and MIB-1 using the avidin-biotin-peroxidase complex technique. A control group of 33 nonmetastasizing PMCs was also analyzed. RESULTS: Immunoreactivity for ret, p53, and MIB-1 showed no difference between metastasizing and nonmetastasizing PMCs. In most tumors, ret was present, while p53 immunoreactivity was absent in all tumors. MIB-1 staining was present in a small number of cells in both groups of tumors. Immunoreactivity for p27 was quantitated by the intensity of expression as well as the distribution of positive cells within each tumor. All tumors showed lower p27 expression than normal thyroid tissue. However, metastasizing PMCs demonstrated a significantly lower expression of p27 than nonmetastasizing PMCs (P<.001). CONCLUSION: Our results suggest that p27 immunohistochemical analysis may be a valuable diagnostic tool in predicting aggressive potential in PMCs.