2005 Volume 44 Issue 4 Pages 250-254
Background: Solitary fibrous tumor (SFT) is a relatively rare soft tissue neoplasm consisting of spindle-shaped fibroblast-like cells with collagen fibers. Signee cytological SFT features have rarely been documented. we report cytological features of a malignant solitary fibrous tumor originating in the pleura.
Case: A pleural mass pointed out in a 71-year-old man in 1997 was biopsied and diagnosed as SFT, and initial resected in 1998. Recurrence in 2003 and a second recurrence in 2004 were detected and resected. Cytological specimens were taken at the first operation and the second recurrence. Sheet-like clusters consisting of spindleshaped cells were seen in the first operation specimen. In the specimen from the second recurrence. small clusters of neoplastic cells with epithelioid features were present. Many neoplastic cells be came round or oval. Histologically. the tumor consisted of spindleshaped cells with stromal collagen in the first operation specimen. Higher cellularity of neoplastic cells with minute foci of necrosis, thought to be a conspicuous change toward malignancy, was seen in the second recurrence specimen.
Conclusion: Round morphological change in neoplastic cells and epithelioid cell clusters may be an important features in malignant transformation in SFT.
