Background: Total thyroidectomy with lymphadenectomy is the most typical operation in a case of papillary thyroid cancer. Range of lymph node resection still remains a matter of controversy. In some publications treatment of lymph node metastases doesn’t affect survival, so only selective lymph node resection is the extended enough operation. The others remark that, local relapse - the worst prognostic factor, appears the most often in the lymph nodes, so they suggest more aggressive treatment. To solve that problem we try to find more sensitive methods to examine lymph nodes.
Aim: To compare the results of detection lymph node metastases of papillary thyroid cancer by immunohistochemistry with the results of RT-PCR for thyroglobulin (Tg) mRNA.
Material and methods: Each of one hundred eighty four cervical lymph nodes obtained from 24 patients, operated in our Department was divided into 2 halves: one was used for conventional histopathology and immunohistochemistry, the other part was investigated by RT-PCR for Tg mRNA. Immunohistochemical staining for Tg was performed on formalin-fixed, paraffin-embedded sections with anti-Tg antibodies.
Results: According to routine, histopathological examination 8 (33.5%) patients had involved lymph nodes. One hundred correspondence of the results of immunohistochemistry and histopathology was observed.
We obtained different results of examination of the lymph nodes in 6 (25%) patients. In four patients (16.7%) RT-PCR was more sensitive in detection of positive lymph nodes, in two patients (8.3%) it revealed less metastasized lymph nodes than immunohistochemistry. The remaining 18 patients didn´t have any differences, fourteen (58.3%) of them had the negative lymph nodes and four (16.7%) had positive, the same lymph nodes in all examinations. Finally, according to RT-PCR 10 (41.7%) of the patients had metastasized lymph nodes.
Conclusion: Tg RT-PCR is a sensitive method of detection of papillary thyroid cancer cells and may help to detect the metastases of papillary thyroid cancer in regional lymph nodes.