A case of PNET, a huge tumor derived from the pleura

Abstract

A 69-year-old female with a huge intrathoracic tumor on chest Xray was referred to our department. We performed a partial resection of the left lower lobe. The pathological findings showed that the tumor consisted of small round cells and was stained positively by the CD99 antibody, resulting in a diagnosis of PNET. PNET is classified according to Ewing's sarcoma family of tumors, so it is important to diagnose it accurately to achieve a better prognosis.