A Case of Intrapulmonary Solitary Fibrous Tumor

Abstract

A 78-year-old man was found having a 40-mm clearly demarcated solid tumor in the lower lobe of the left lung on a chest CT scan during examination and treatment for bronchial asthma. A PET-CT showed high accumulation of FDG with the SUV max of 2.4 to the tumor. A bronchoscopic biopsy failed to give the definite diagnosis, but the tumor enlarged, we performed video-assisted thoracoscopic left lower lobectomy and mediastinal lymph node dissection (ND2a-1). Macroscopic findings of the resected specimen revealed a clearly demarcated tumor which was white in color and was not contiguous to the visceral pleura. Histopathology showed the tumor to be composed of spindle-shaped cells which were complicated in a fascicular manner. In immunohistochemical staining, the tumor cells were CD34(+), STAT6(+), and S-100(-). The tumor was finally diagnosed as intrapulmonary solitary fibrous tumor. The tumor was less than 5 cm in diameter and had no necrotic features. The mitotic count was less than 3 per 10 high power fields (/10HPF). There were no findings suggestive of malignancy. We present a rare case of intrapulmonary solitary fibrous tumor.