Retrospective radiographic analysis of nonpedunculated colorectal carcinomas with special reference to tumor doubling time and morphological change

OBJECTIVE: Our aim was to characterize the development of nonpedunculated c olorectal carcinomas by retrospective radiographic analysis, with special r eference to tumor doubling time and morphological change. METHODS: Eleven colorectal carcinomas, which were observed for >6 months by barium enema examinations, were collected and retrospectively reviewed. Th ere were five early and six advanced carcinomas, including submucosally inv asive, superficial depressed carcinomas. RESULTS: Mean diameter of lesions at initial barium enema examination was 1 3.5 mm (early, 10.4 mm; advanced, 16.0 mm) and that at final barium enema e xamination was 30.9 mm (early, 18.2 mm; advanced, 41.5 mm). Initial morphol ogy of the lesions was superficial in three, sessile in seven, and semipedu nculated in 1. There was no pedunculated lesion. Macroscopic morphology of the five early carcinomas was superficial depressed (IIc) in two cases, mos tly depressed but partly elevated (IIc+IIa) in one case, and superficial el evated with a depressed component (IIa+IIc) in two cases; all of the advanc ed carcinomas were of the ulcerated type. Mean doubling time was 6.8 months (early, 9.4 months; advanced, 4.7 months). Early carcinomas had significan tly longer doubling times than advanced carcinomas (p = 0.017, Wilcoxon's t ext). The lesions with the longest doubling times were superficial depresse d lesions. CONCLUSIONS: Early carcinomas have longer doubling times than advanced carc inomas. Most nonpedunculated colorectal carcinomas grow without significant morphological changes. Superficial depressed type tumors grow slowly, main taining their macroscopic morphology. (C) 2000 by Am. Coll. of Gastroentero logy).