Mucosal Prolapse / Cloacogenic Polyp
Differential Diagnosis
| Mucosal Prolapse / Cloacogenic Polyp |
Peutz-Jeghers Polyp |
| Usually solitary polyp |
Usually multiple |
| Smooth muscle surrounds individual crypts |
Prominent arborizing smooth muscle bundles surround groups of crypts |
| Polyps rare in small intestine |
Most polyps in small intestine |
| Not associated with oral pigmentation |
Associated with oral pigmentation |
| Usually eroded surface |
Erosion infrequent |
| Mucosal Prolapse / Cloacogenic Polyp |
Colorectal Adenoma |
| Nuclear atypia most prominent deep in the lesion with surface maturation |
Nuclear atypia involves surface of polyp |
| Nuclei usually enlarged but round and not stratified and not densely packed |
Nuclei elongated, hyperchromatic, densely packed and frequently stratified |
| Apoptosis not prominent |
Prominent apoptosis |
| Mucosal Prolapse / Cloacogenic Polyp |
Sporadic Juvenile Polyp |
| Surface erosions with granulation tissue frequent |
Surface erosions infrequent |
| Irregular glands with scattered dilation |
Prominent, regularly dilated glands |
| Smooth muscle extension into lamina propria of polyps |
No prominent smooth muscle in lamina propria of polyps |
| Most in rectum or sigmoid |
May involve any part of colorectum |
| Mucosal Prolapse / Cloacogenic Polyp |
Cowden Disease, Colorectal Polyp |
| Surface erosions with granulation tissue frequent |
Surface erosions infrequent |
| Polypoid |
Sessile |
| Prominent smooth muscle extension into lamina propria of polyps |
Smooth muscle in lamina propria usually not promiinent |
| No associated lesions |
Most have facial and oral papillomas, fibromas and skin tumors, see description LINK |
| No genetic abnormality |
PTEN mutations in 80% |
| Mucosal Prolapse / Cloacogenic Polyp |
Reactive / Inflammatory Polyp |
| Smooth muscle extension into lamina propria of polyps |
No smooth muscle in lamina propria of polyps |
| Usually localized to rectum |
Usually multiple, may involve any inflamed area |
| Not associated with inflammatory bowel disease |
Usually associated with ulcerative colitis but may be sporadic |
| Mucosal Prolapse / Cloacogenic Polyp |
GI Perineurioma |
| Fibrovascular stroma |
Lacks vascularity |
| Inflammatory infiltrate |
Inflammation infrequent |
| Prominent gland component |
Mostly a spindled stromal lesion, crypts pushed aside |
| Villiform eroded surface |
Surface intact and normal |
| Smooth muscle extends into lamina propria around crypts |
Lamina propria spindled lesion is smooth muscle actin negative and positive for perineurial markers |
| Mucosal Prolapse / Cloacogenic Polyp (Localized Colitis Cystica Profunda) |
Invasive Colorectal Adenocarcinoma |
| No surface carcinoma component |
Surface component usually present |
| No high grade nuclear atypia |
High grade nuclear atypia usually present |
| No cribriform glands or complex architecture |
Complex architecture with cribriform glands frequent |
| No desmoplastic stromal response |
Desmoplastic stromal response |
| Lamina propria may accompany displaced glands |
No lamina propria accompanying invasive glands |
| Mean age 35 years |
Occurs in older patients |
