Gastrointestinal Tract Perineurioma
Definition
- Gastrointestinal tract mesenchymal neoplasm exhibiting features of perineurial cell differentiation
Alternate/Historical Terms
- Fibroblastic polyp of the colon
Diagnostic Criteria
- Circumscribed expansion of lamina propria
- Usually limited by disrupted muscularis mucosae
- Infrequent cases may extend into submucosa
- May be separated from overlying surface mucosa by a narrow zone of normal lamina propria
- Separates, entraps and distorts crypts
- Composed of uniform, bland spindled cells
- Oval to elongate nuclei
- No pleomorphism, atypia or mitotic figures
- Pale indistinct cytoplasm
- Virtually restricted to left colon and rectum
- Rarely in right colon or small intestine
- Entrapped crypts frequently hyperplastic/serrated 50-70% of cases
- Changes of hyperplastic polyp or sessile serrated adenoma may occasionally predominate
- In such lesions, the perineurioma may surround just one or two crypts (Pai 2011)
- Changes of hyperplastic polyp or sessile serrated adenoma may occasionally predominate
- Usually ≤10 mm
- Rarely up to 4.5 cm
- Positive for markers of perineurial cells (see Supplemental Studies)
- Lesions reported as GI tract fibroblastic polyp appear to be the same lesion as perineurioma
Robert V Rouse MD
Department of Pathology
Stanford University School of Medicine
Stanford CA 94305-5342
Original posting/updates : 11/29/09, 10/26/10, 3/28/11, 11/11/11
