Diagnostic pitfalls in the preoperative 18F-FDG PET/CT evaluation of a case of giant malignant solitary fibrous tumor of the pleura.

Solitary fibrous tumor of the pleura (SFTP) is an uncommon entity, generally with an indolent behavior. Nevertheless, some malignant forms have been rarely reported. These, often have an aggressive biological behavior with pathological findings of invasiveness. The preoperative diagnosis and evaluation of the grade of malignancy are extremely challenging. Herein we report a case of a 64-year-old man who presented with a left giant intra-thoracic mass imaged with fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography ((18)F-FDG/PET-CT) and sampled via fine-needle aspiration biopsy (FNAB). Imaging and FNAB findings showed suspicion of a benign form of SFTP. Surgical radical resection of the giant mass was performed. The definitive histological diagnosis showed a malignant SFTP. Based on this report, we take the opportunity to briefly discuss the insidious pitfalls concerning the radiological and (18)F-FDG/PET-CT features as well as cyto/histological findings in the pre-operative diagnostic work-up examination of this rare entity.