Mucosal Schwann Cell Hamartoma
Definition
- Intramucosal infiltrate of S100 positive spindled cells lacking other neural elements
Diagnostic Criteria
- Lamina propria expanded by an infiltrate of spindled cells
- Indistinct borders
- Surrounds and entraps crypts
- Uniform bland spindled cells
- Abundant dense eosinophilic cytoplasm
- Indistinct cell borders
- No atypia, pleomorphism or mitotic activity
- No ganglion cells in lesion
- Axons very rare to absent
- Extensively S100 positive
- Negative for GFAP, claudin1, CD34, CD117, smooth muscle actin
- All reported cases occur in the colorectum
- Most are distal
- 1-6 mm in size
- No relationship to familial syndromes
- Benign
- No recurrence
Robert V Rouse MD
Department of Pathology
Stanford University School of Medicine
Stanford CA 94305-5342
Original posting : November 29, 2009
