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Vol.38 No.7 contents | Japanese/English |
- Original Article -
Solitary Fibrous Tumors of the Pleura with Special Reference to Histogenesis and Biological Behavior
Shinya Okada, Yoshiro Ebihara, Motoshige Kudo, Hiromi Serizawa*, and Harubumi Kato**The Second Department of Pathology, Department of Surgical Pathology*, and First Department of Surgery**, Tokyo Medical University
Twenty-three foci in 20 cases of solitary (localized) fibrous tumor of the pleura (SFTP) were studied to ascertain their immunohistochemical and electron microscopical characteristics and the biological behavior. The tumors were pedunculated and solid and had arisen from either visceral or parietal pleura. Microscopically, SFTPs presented diverse features from sclerotic to cellular,but basically showed a "patternless" pattern. Seven tumors were sclerotic type, 8 were cellular type and the remaining 8 were mixed type. Ultrastructurally, the tumor cells were classified into three types: spindle cells with profiles of long thin cytoplasmic processes and dendritic cells with complicated processes simulating dendrites of ganglion cells and intermediate cells. Spindle cell type were typical of the tumor cells. Dendritic cells were characteristic of the cellular and mixed tumor types. Immunohistochemically, the tumors stained positively with vimentin (100%) and CD34 (73%). In addition, they were positive for synaptophysin, neurofilament, S-100 protein, MIC-2, NGFR, SMA and desmin. Two recurrent cases had a high degree of cell atypia, with occasional intranuclear cytoplasmic inclusions, nuclear grooves and multinucleation. They were highly positive for p53, ki-67 and PCNA. Cell atypia and cellularity were considered to be two important factors in evaluating the malignancy of the tumors. The present results suggest that the origin of SFTP may be undifferentiated mesenchymal cells with multipotential differentiation toward either neurons or muscle.
key words: Solitary fibrous tumor, Pleura, Immunohistochemistory, Electron microscopy, Histogenesis
Received: August 11, 1998
Accepted: September 30, 1998
JJLC 38 (7): 825-835, 1998
