Detection of lymph node metastases of papillary thyroid cancer-comparison of the results of histopathology, immunohistochemistry and reverse transcription-polymerase chain reaction-a preliminary report.

BACKGROUND: The range of lymphadenectomy in differentiated thyroid cancer remains still a matter of controversy because of the lack of reliable diagnostic methods for nodal metastases, other than histopathology. AIM: To compare the results of detection of lymph node metastases of papillary thyroid cancer by conventional histopathology and immunohistochemistry with the results of reverse transcription-polymerase chain reaction for thyroglobulin mRNA. PATIENTS AND METHODS: Each of 166 cervical lymph nodes obtained from 21 patients was divided into two halves: one was used for conventional histopathology and immunohistochemistry, the other part was investigated by molecular examination. RESULTS: We obtained different results from examination of the lymph nodes in six (28.6%) patients. In four patients (19.1%) reverse transcription-polymerase chain reaction (RT-PCR) was more sensitive in detection of positive lymph nodes; in two patients (9.5%) it revealed fewer metastasised lymph nodes than did histopathology. The rest of the patients did not have any differences: 12 (57.1%) of them had negative lymph nodes and three (14.3%) had positive lymph nodes in all examinations. CONCLUSIONS: (1) Thyroglobulin (Tg) RT-PCR is an appropriate method of detection for thyroid cancer cells. (2) In combination with histopathology, it might help to qualify patients' nodal status better.

Carcinogenic effect of combined administration of 2,4-diaminoanisole sulfate, 4,4'-thiodianiline and N,N'-diethylthiourea in male Wistar rats.

Male Wistar rats were divided into two groups. Rats of group 1 were fed basal powdered diet containing 610 ppm 2,4- diaminoanisole sulfate (DAAS), 46 ppm 4,4'-thiodianiline (TDA) and 200 ppm N,N'-diethylthiourea (DETU) for 52 weeks (DTD treatment). Rats of group 2 were maintained on basal diet throughout the experiment as controls. At 52 weeks all surviving rats were sacrificed and subjected to an autopsy. Thyroid, lungs, stomach, liver, spleen, kidneys, testes and all gross lesions suspected of being a tumor were removed. After DTD treatment, the incidence of thyroid hyperplasia and papillary thyroid carcinoma was 59% (10/17) and 65% (11/17), respectively. Hepatocellular adenoma was induced in 2 of 17 rats (12%). Papillary thyroid carcinoma metastasis was found in the lung of 1 rat. No neoplastic tumors were found in kidney, spleen, stomach and testis tissue.

The influence of a single acetic acid and lactic acid injection on rat normal thyroid tissue.

Until now, the use of acetic and lactic acid for the treatment of thyroid nodular lesions, as well as histopathologic changes in the thyroid tissue after their intrathyroidal injections has not been described. The aim of this study is to evaluate macro- and microscopic changes in rat normal thyroid tissue induced by single intrathyroidal injection of acetic acid (AA) and lactic acid (LA) in different concentrations, as well as the influence of intrathyroidal acid injection on function of the recurrent laryngeal nerves. Male Wistar rats were divided into two groups of 50 (Group A and B). Rats of each group were divided into the subgroups of five. In each subgroup of Group A and B, AA and LA water solutions of different concentrations (0%, 2.5%, 5%, 10%, 20%, 30%, 40%, 50%, 60%, 80%), respectively, were injected into the right thyroid lobe. From Group A and B, 7 and 8 rats died, respectively (after injections of 50-80% AA and LA solutions). After 4 weeks post AA or LA injection the thyroid along with the surrounding tissues was excised and assessed macro- and microscopically in all rats that survived. Before the injection and just before the second operation, the vocal cord function was evaluated. Our results show that both, acetic and lactic acid of different concentrations damage rat normal thyroid tissue after a single intrathyroidal injection. The minimal concentrations of acetic and lactic acid that cause lethal changes in rat normal thyroid tissue are 20% and 10%, respectively. Acetic and lactic acid in the concentrations of 40% and 50%, respectively, and higher can cause injury of the tissues adjacent to the thyroid.

Expression of proteins: D1 cyclin and Ki-67 in papillary thyroid carcinomas.

The aim of the study was an evaluation of expression of D1 cyclin and Ki-67 proteins in tissue of human papillary thyroid carcinoma (PTC) in a group of papillary microcarcinomas and in a group of PTC with a degree of staging higher than pT1a in TNM classification. We performed immunohistochemical staining and found no statistical differences between groups. These results suggest that changes of expression of D1 cyclin are an early event in tumorigenesis.

Thyroid cryotherapy in an experimental rat model.

In recent years cryotherapy has been more and more frequently used for the treatment of tumors of different organs. Until now, the use of cryotherapy for the treatment of thyroid lesions, as well as histopathologic changes in thyroid tissue after cryotherapy, has not been described. Nitrous oxide cryotherapy of one thyroid lobe in twenty 12-week male Wistar rats was performed. After 2 and 4 weeks, the cryotreated thyroid lobe and the second lobe along with a part of the trachea, esophagus, and the subhyoid muscles adhering to the thyroid were excised and assessed macro- and microscopically. The macroscopic evaluation, performed 2 and 4 weeks postcryotherapy, revealed atrophy of the cryotreated lobe in 4 and 3 rats, respectively, and reduction of the cryotreated lobe dimensions in 6 and 7 rats, respectively. In the specimens of the lobes excised 2 weeks following cryotherapy, examined microscopically, necrosis, granulomatous inflammation, hemorrhages, and hemosiderin deposits were found most often, whereas in the specimens of the lobe excised after 4 weeks lymphocytic inflammation and fibrosis were mainly observed. No microscopic changes were observed in the thyroid lobes that were not frozen or in the parathyroid glands located inside these lobes or extrathyroidally, either ipsilaterally or contralaterally to the cryotreated thyroid lobes. There was no microscopic damage to other tissues adjacent to the thyroid gland. No rat developed vocal cord dysfunction after cryotherapy and no significant changes in serum calcium level before and after cryotherapy were observed. The results obtained show that it is possible to cryoblate thyroid tissue without damaging the tissues adjacent to the thyroid, as well as to spare function of the recurrent laryngeal nerves and parathyroid glands.