Tomografia de Emissão de Positrões no diagnóstico do tumor oculto Positron Emission Tomography in the diagnosis of an unknown primary tumour

In Internal Medicine we are frequently confronted with the diagnosis of advanced malignant disease, in patients without previous tumour diagnosis. The localization of the primary tumour is fundamental for the patient treatment. In some cases, although exhaustive investigation is carried out, the primary site remains obscure, even in the presence of metastasis. The Positron Emission Tomography (PET), using 18Fluoro-DGlucose (18FDG) is a whole body, multi-organ, non invasive exam, used to diagnose and stage a large number of malignancies, including the occult tumour. We present two female patients with advanced malignant disease, in whom the 18FDG-PET was essential for the diagnosis.