General
=========================================================================

• Resembles solitary fibrous tumor but prominent vessels
• 30% recur, 15% metastasize (lung, liver, bone, regional lymph nodes), usually late
• Histology does not predict behavior (Hum Pathol 1982;13:210)

Case reports
=========================================================================

• 66 year old woman with left eye proptosis, ptosis, and blindness (Arch Pathol Lab Med 2002;126:1555)

Micro description
=========================================================================

• Usually encapsulated
• Random pattern of polygonal and rounded cells with ill defined cytoplasm, variable nucleoli
• Staghorn vascular pattern and perivascular collagen, dense pericellular reticulin, occasional mitotic figures
• Must rule out other tumors with this pattern

Micro images
=========================================================================

Small polyhedral cells surround vascular spaces

Vascular channels have a staghorn pattern

Cells are polyhedral and spindled, with mild atypia

Metastatic liver nodule

A-large left orbital mass; B-random pattern of polygonal and rounded cells C-large and small vessels with staghorn pattern; D-reticulin densely surrounds each cell

Positive stains
=========================================================================

• CD34 (focal or weak), dense pericellular reticulin staining, vimentin
• Variable XIIIa

Negative stains
=========================================================================

• EMA, GFAP, S100, keratin, desmin, muscle specific actin, smooth muscle actin

Differential diagnosis
=========================================================================

• Fibrous histiocytoma: predominant storiform pattern; foam cells and giant cells present
• Meningiomas: EMA+, complex interdigitating processes and desmosomes by EM, deletions of #22
• Solitary fibrous tumor: CD34 strongly+

This information is intended for physicians and related personnel, who understand that medical information is often imperfect, and must be interpreted in the context of a patient's clinical data using reasonable medical judgment. This website should not be used as a substitute for the advice of a licensed physician.

All information on this website is protected by copyright of PathologyOutlines.com, Inc. Information from third parties may also be protected by copyright. Please contact us at copyrightPathOut@gmail.com with any questions (click here for other contact information).