A 37-year-old woman presents with a right groin mass, clinically suspicious for vascular origin. The excised mass revealed an 8 x 6 x 4 cm soft nodule with a lobulated and glistening cut surface. H&E stained sections and an immunostain for CD34 are shown. Tumor cells are negative for S100, EMA, MUC4, CD31, Desmin and ERG, and Ki67 proliferation index is low (~2%). What is your diagnosis?

A. Hemangioendothelioma 

B. Peripheral nerve sheath tumor (PNST)

C. Myxoid liposarcoma

D. Solitary fibrous tumor

E. Spindle cell lipoma