A Large Benign Solitary Fibrous Tumor in the Pelvis: A Unique Group.

Solitary fibrous tumors (SFTs) are a rare type of sarcoma and ubiquitous in nature, occurring anywhere in the body. Although only a few hundred cases have been described so far, certain histological features, such as hypercellularity and high mitotic index, have been associated with a more malignant course. Tumor sizes larger than 10 cm have also been associated with higher recurrence rates. There are clinical recommendations for two distinct patient groups, those with small and benign SFTs or those with large and malignant SFTs. There are few that acknowledge the unique group of those with large but benign tumors. A case involving a 62-year-old man who underwent surgical resection of a large but benign solitary fibrous tumor of the pelvis is described.