Further studies on the histological characteristics linked to local tumour invasion in colorectal carcinomas.
Cross-sectional slicing of the specimen (large histological sections) from 112 consecutive surgical specimens having a colonic (n = 79) or a rectal (n = 33) adenocarcinoma were reviewed. Neoplastic glands with a thin layer of neoplastic cells were present at the growing tumour edge in 32.8% of the colonic carcinomas and in 35.7% of the rectal carcinomas. Glands lacking part of the neoplastic epithelium at the growing edge (i.e. with glandular "pore" formation) were found in 80.5% of the colonic carcinomas and in 85.7% of the rectal carcinomas. The possibility that the thin layer of tumour cells in neoplastic glands antedated the formation of glandular "pores" was entertained. From the results it would appear that at the growing edge of colorectal carcinomas, neoplastic glands usually develop epithelial "pores". The contents of those neoplastic glands, namely mucin, inflammatory cells and/or necrotic material, are released through those "pores" into the surrounding host tissues. Those materials, rich in proteolytic enzymes, would encourage the degradation of the juxtaposed matrix of the host. To restore the continuity of those incomplete glands, new cancer cells would grow around the mucin "lakes" or the inflammatory-necrotic aggregates free in the stroma. This mechanism guarantees a lifelong tumour progression in untreated patients. Since preoperative irradiation was administered only to patients carrying rectal tumours, it is apparent that the histological features here described are neither evoked nor abrogated by irradiation.
Rubio
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CA
Gastrointestinal and Liver Pathology Research Laboratory, Department of Pathology, Karolinska Institute and Hospital, 171 76 Stockholm, Sweden. Carlos.Rubio@onkpat.ki.se
D000230:Adenocarcinoma / Q000473:pathology*; D015179:Colorectal Neoplasms / Q000473:pathology*; D006801:Humans; D009361:Neoplasm Invasiveness