Some adenomatous polyps may progress to adenocarcinoma, while others may not. Certain features of a polyp may indicate an increased risk for malignant transformation.
Risk factors:
(1) size
(2) appearance
(3) dysplasia
(4) squamous metaplasia
(5) architecture
(6) number of polyps
Risk Factor |
Low Risk |
Intermediate Risk |
High Risk |
size |
small (< 1.0 cm) |
1.0 – 1.5 cm |
large (> 1.5 cm) |
appearance |
pedunculated |
|
flat or sessile |
dysplasia |
none or mild |
moderate |
severe |
squamous metaplasia |
absent |
|
present |
architecture |
tubular |
tubulovillous |
villous |
number of polyps |
one |
two (?or three) |
multiple polyps |
after table on page 887
Interpretation:
• A polyp with features indicating a high risk of malignant transformation needs to be completely excised if possible, else closely monitored.
Purpose: To evaluate an adenomatous colonic polyp for risk factors of malignant transformation.
Specialty: Gastroenterology
Objective: risk factors
ICD-10: K63.5,