wy1992: I can not call myself an expert on soft tissue pathology.  I just want to offer my observation and one possible differential diagnosis.  This appears to be benign fibroblastic proliferation, probably a low grade fibroblastic tumor; although we have to rule out that it is not a reactive process.  On slide 2, there is a one focus of possibly dilated mucinous gland surrounded by ovarian type stroma.  Also seen on the surface is a simple lining epithelium - hard to characterize, may be mesothelial cells.  There are also many dilated thin and occasional thick walled vessels as well.  Some stromal cells also have clear cystoplasm.  With all these observations, I wonder whether this might be a tumor related to ovarian fibroma/thecoma.  Examination of entire lesion paying attention to cytologic atypia, mitoses and necrosis to rule out any possibility of sarcoma is the most important.  Additional clinical history and IHC might be helpful as well.  Thanks for sending me the message. I look forward to hearing your final answer.

Thanks!You are suspicious of a tumor related to ovarian fibroma/thecoma.I think that's really a good thinking way.Thanks anyway