Solitary Fibrous Tumor of the Pleura – Description of Two Cases withFeatures of Malignancy

Overview

Two cases of solitary fibrous tumor of the pleura with features of malignancy are described. Inthe first case, the tumor macroscopically showed noncircumscribed growth. Microscopically, onlow power examination, the tumor was characteristically „patternless“, with alternation of cellularareas and hypocellular, prominently collagenized areas. There was an infiltrative growthpresent at the margins. Cytological atypias were not present. In the second case, the tumor wasmacroscopically circumscribed. Microscopically, on low power examination, the tumor had characteristical„patternless“ appearance again. Pleomorphic cells with high mitotic activity dominatedin cellular areas on high power examination. The infiltrative pattern of growth was notpresent at the margins. Both tumors were classified as malignant solitary fibrous tumors of thepleura, or fibrosarcomas of the pleura. The criteria of malignancy for solitary fibrous tumor arediscussed.

Key words:
solitary fibrous tumor – malignancy