The role of myofibroblasts at the tumor border of invasive colorectal adenocarcinomas.
BACKGROUND
In order to elucidate the significance of myofibroblasts in invasive growth of colorectal adenocarcinomas, we examined the number of myofibroblasts at the tumor border of colorectal adenocarcinomas.


METHODS
A total of 91 invasive colorectal adenocarcinomas were examined immunohistochemically using anti-alpha-smooth muscle actin (ASMA) and high-molecular-weight caldesmon (h-CD) antibodies; 25 carcinomas confined to the submucosa (sm carcinomas), 40 carcinomas confined to the muscularis propria (mp carcinomas) and 26 carcinomas invading the subserosa or adventitia (ss carcinomas). We considered ASMA-positive and h-CD-negative stromal cells as myofibroblasts.


RESULTS
Twenty-seven (67%) of the 40 mp carcinomas and 25 (96%) of the 26 ss carcinomas had a small number of myofibroblasts at the tumor border facing the muscularis propria.


CONCLUSIONS
Although direct evidence is lacking, there is a possibility that the further immediately vertical and radial invasion of carcinoma cells into the subserosa or adventitia is associated with a smaller number of myofibroblasts at the tumor border facing the muscularis propria in mp carcinomas, resulting in a low incidence of mp and a high incidence of ss carcinomas in the colorectum.
Nakayama
H
H
First Department of Pathology, Kochi Medical School, Japan. nakayamh@kochi-ms.ac.jp
Enzan
H
H
Miyazaki
E
E
Naruse
K
K
Kiyoku
H
H
Hiroi
M
M
D000230:Adenocarcinoma / Q000473:pathology*; D002452:Cell Count; D016009:Chi-Square Distribution; D015179:Colorectal Neoplasms / Q000473:pathology*; D005347:Fibroblasts / Q000502:physiology*; D006801:Humans; D009130:Muscle, Smooth / Q000166:cytology*; D009361:Neoplasm Invasiveness