Palmar Fibromatosis

Definition

A nodular, cytologically bland fibroproliferative process that involves the palmar aponeuroses

Most often involves palm
- May rarely involve dorsum of hand or wrist
Involves aponeurosis and rarely overlying dermis
- No infiltration of deeper tissues
Grossly forms multiple nodules 1 cm or less
- Infrequently forms a single dominant nodule
Cellularity ranges from low to high
- Older lesions are densely collagenous
Bland spindle cells
- Nuclei small and dark to moderate sized and vesicular
- Scant cytoplasm
- Mitotic figures may be frequent but not atypical
Small foci of perivascular hemorrhage and hemosiderin may be present
Metaplastic cartilage and bone are seen rarely
Necrosis very rare

Robert V Rouse MD
Department of Pathology
Stanford University School of Medicine
Stanford CA 94305-5342

Original posting: November 29, 2007