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

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. 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. 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. 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. (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.