Cytological and immunocytochemical evaluation of thyroid and breast masses in patients with a previous neoplasm: Case reports

The diagnosis of secondary tumours represents one of the most important fields in the application of fine needle aspiration cytology (FNAC). We studied two patients, one with a history of breast cancer and one with a previous tumour of the thyroid, who showed a second mass, in the thyroid and in the breast, respectively, during follow up. The aim of our study was to evaluate if cytology, performed on FNAC smears, may distinguish a metastatic lesion from a second primary tumour, or if further immunocytochemistry should be performed. Our data demonstrate that, while cytology may be indicative of a second primary tumour, the histotype should be confirmed by immunocytochemical staining.