Original Article Invasive carcinomas may arise in colorectal adenomas with high grade dysplasia and with carcinoma in situ
Carlos A. Rubio, John G. Delinassios
Department of Pathology, Karolinska University Hospital and Institute, Stockholm, Sweden and International Institute of Anticancer Research, Kapandriti, Attiki, Greece.
Received December 18, 2009; accepted January 5, 2010; available online January 10, 2010
Abstract: Colorectal carcinomas (CRC) usually arise in colorectal adenomas (CRA) displaying high-grade dysplasia (HGD) or carcinoma in situ (CIS). The aim was to assess in a cohort of consecutive CRA with submucosal invasive carcinoma, the frequency of adenomas displaying HGD or CIS. Ninety-two consecutive adenomas were investigated. Submucosal invasion was present in the 39 adenomas with HGD (42%) and in 58% (53/92) of the adenomas with CIS (p<0.05). Sections from 49 adenomas were stained with the DNA-specific Feulgen reaction and with the proliferation marker Ki-67. Five consecutive high power fields (HPFs) were evaluated using a x40 objective. Marked Feulgen reaction was recorded in 91.8% or in 101 of the 110 HPFs studied in adenomas with HGD, but in none of the 135 HPFs studied in adenomas with CIS (p<0.05). Intense Ki67 expression (≥75%) was present in 98.2% or in 108 of the 110 HPFs studied in adenomas with HGD, but only in 1.4% or in 2 of the 135 HPFs in adenomas with CIS (p<0.05). Hence, HGD cells and CIS cells can be differentiated not only morphologically but also chemically by the semiquantitative appreciation of their DNA content and immunohistochemically by the apparent difference in cell proliferation. Although submucosal invasion occurred significantly more frequently in adenomas with CIS than in those with HGD, as much as 42% of the adenomas with submucosal invasion displayed HGD at histology. Despite morphological, chemical and immunhistochemical dissimilarities, these 2 non-invasive neoplasias might have an apparent similar biological behaviour in terms of progression towards submucosal invasion. (IJCEM912006).
Address all correspondence to: John G Delinassios, PhD International Institute of Anticancer Research 1st km Kapandritiou-Kalamou Rd. PO Box 22, Kapandriti, Attiki, 19014 Greece E-mail: firstname.lastname@example.org