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.