Preoperative diagnosis of thyroid carcinomas by aspiration biopsy-reverse transcription-polymerase chain reaction (ABRP): A report of two cases

A preoperative molecular-based diagnostic technique for thyroid papillary a nd anaplastic carcinomas was recently developed to detect oncofetal fibrone ctin (onfFN) messenger RNA (mRNA) in fine needle aspiration biopsy (FNAB) b y means of reverse transcription-polymerase chain reaction (RT-PCR). We rep ort two cases of thyroid tumors, in which cytological diagnosis was not suc cessful but in which RT-PCR analysis provided information that helped to id entify the biological features of the tumors. One case could not be diagnos ed by aspiration biopsy cytology (ABC) because of poor fixation; however, R T-PCR did detect the expression of onfFN mRNA, which suggested the existenc e of papillary carcinoma cells. After surgery, this tumor was diagnosed as a papillary carcinoma by histological examination. The other case was diagn osed as a papillary carcinoma by ABC, but onfFN mRNA was not detected in th e FNAB by RT-PCR, The neoplasm was diagnosed as a follicular tumor by histo logical examination. These cases suggest the benefits of combining both gen etic and cytological approaches to the examination of FNAB.