Table 3 Comparison of colorectal perineurioma with entities in the differential diagnosis
From: Colonic perineurioma (benign fibroblastic polyp): case report and review of the literature
Perineurioma | GIST [25] | Schwann cell hamartoma [21] | Ganglio-neuroma [25] | Neurofibroma [21] | Schwannoma [26] | Inflammatory fibroid polyp [25] | Inflammatory myoglandular polyp [20] | Leiomyoma of the MM [27] | |
|---|---|---|---|---|---|---|---|---|---|
Most common location | Distal colon | Stomach, small bowel | Distal colon | Distal colon | Stomach, small bowel | Stomach | Stomach, ileum | Distal colon | Distal colon |
Epicentre | Mucosa | MP | Mucosa | Mucosa | Submucosa | MP | Submucosa | Mucosa | MM |
Typical size | < 10 mm | Two-thirds > 50 mm | ≤5 mm | 10 - 20 mm | Wide size range | > 10 mm | 10 - 50 mm | 5 - 20 mm | < 10 mm |
Histological clues | Entrapped serrated crypts, peri-cryptic growth, bland cytology | Spindled to epithelioid, variable palisading, paranuclear vacuoles, collagen fibrils | Ample eosinophilic cytoplasm, no serration in entrapped crypts | Ganglion cells present | Diverse cellular composition: Schwann cells, fibroblasts, perineurial-like cells, axons | Circumscribed, peripheral lymphoid cuff with germinal centres, focal atypia | Many eosinophils, perivascular concentric cuffing, fibromyxoid background | Inflamed granulation tissue, proliferation of smooth muscle in LP, occasional cystic glands | Originates from MM, circum-scribed, eosinophilic cytoplasm |
Positive IHC stains | EMA, claudin1, GLUT1 | C-Kit, DOG1, CD34 | S100 (all cells), NFP (rare) | S100 in spindled cells | S100 (subset of cells), CD34 | S100, GFAP | CD34, cyclin D1, fascin | SMA, desmin in smooth muscle | SMA, desmin |