[Differential criteria between papillary and follicular thyroid carcinoma--initial conclusions from a multicenter trial]. / Kryteria róznicowania miedzy rakiem brodawkowatym i pecherzykowym tarczycy--pierwsze wnioski z badania wieloosrodkowego.

Histopathological diagnosis of thyroid cancer is difficult and requires much experience. Pathologists have to know many histopathological variants and be aware of the current diagnostic criteria. The aim of the study was to unify criteria applied all over the country and compare whether the accuracy of diagnosis has changed in the course of the last fifteen years. In a multicenter trial, 36 pathologists from 25 centers reevaluated 232 thyroid tumors operated between 1985-1998. The reference diagnosis was given on the basis of evaluation made by four experienced pathologists. The two-step analysis was performed. At first, the accuracy of the diagnosis of malignant neoplasm was evaluated. Then, the accuracy of the diagnosis of the cancer histotype was analyzed, with estimation of kappa coefficients and their asymptomatic standard error. Comparison of primary and reference diagnoses revealed statistically significant differences--in 17% of cases the primary diagnosis of cancer was not confirmed by experienced pathologists. Kappa coefficient for the diagnosis of cancer histotype was 0.53 + 0.06. On the contrary, the diagnoses made by the participants of the trial did not differ significantly from the reference ones. Kappa coefficient for the diagnosis of cancer histotype was significantly higher than for primary diagnoses with 0.63 +/- 0.10 (p < 0.001). The first results of the multicenter trial indicated that the most frequent diagnostic error made at primary diagnosis was the overdiagnosis of follicular thyroid carcinoma. Thus, a summary of strict criteria for papillary and follicular thyroid carcinoma is also given.

[Criteria for histopathologic diagnosis of thyroid cancer in a quick test of accuracy]. / Kryteria rozpoznania histopatologicznego raka tarczycy w szybkim tescie zgodnosci.

A quick test of accuracy of histopathological diagnosis of thyroid carcinoma was performed in May 2000 during the meeting of Polish thyroid cancer group (Committee for Epidemiology, Diagnosis and Treatment of Thyroid Carcinoma). 29 pathologists participated in the test and evaluated 8 cases of thyroid carcinoma and 14 benign thyroid lesions. All cases were chosen from the current material sent for pathologic evaluation to the Institute of Oncology in Gliwice due to diagnostic difficulties. In total, 591 diagnoses were made and were the subject of the presented analysis. They were compared with reference diagnosis in two aspects. First, the accuracy of the distinction between malignant and benign lesions was evaluated. 72.5% of diagnoses were concordant with the reference. The false diagnosis of cancer in a benign lesion was observed 133 times (22.5% of all diagnoses). A reverse error--a false exclusion of cancer--was seen in 29 diagnoses (4.9%). Chi 2 test revealed a statistically significant difference between the participants' diagnoses and reference ones (p < 0.0001). Overdiagnosis of cancer was the most frequent at the diagnosis of follicular or oxyphilic cancer. With reference to the diagnosis of cancer histotype, concordant diagnoses were seen in 40-47% of cases with the lowest accuracy of the diagnosis of oxyphilic (40% of correct diagnoses) and follicular (50%) cancer. The causes of false diagnoses may be divided in two groups: sample-related causes (sampling of surgical specimens, lack of standard description, insufficient number of samples, poor quality of staining) and diagnostic errors: non-compliance with diagnostic criteria and inappropriate setting of diagnoses, which require immunohistochemical confirmation.

[Prognostic significance of selected oncogene and suppressor gene expression in follicular thyroid carcinoma]. / Prognostyczne znaczenie ekspresji wybranych onkogenów i genów supresorowych w raku pecherzykowym tarczycy.

Oncogene and suppressor gene expression (cyclin D, p21WAF1, nm23-H1, Rb1, p16INK4A, and p53) was evaluated in 23 follicular thyroid carcinomas diagnosed in 20 women and 3 men operated or reoperated in Institute of Oncology in Gliwice in years 1992-1999. Positive reaction with p16INK4A, Rb1 and cyclin D1 antibodies was observed in all tumors, with nm23-H1 in 22 cases. The presence of p21WAF1 was stated in 8 cases (34.8%) and p53 in 7 cases (30.4%). A simultaneous presence of expression of p53 and lack of expression of p21WAF1 was stated three times and in two cases were accompanied by distant metastases. This pattern of expression was only rarely observed in minimally invasive follicular cancer. The prognostic significance of simultaneous immunohistochemical analysis of p53 and p21WAF1 in follicular thyroid carcinoma is suggested and has to be proved in further studies.