Intramucosal carcinoma on biopsy reliably predicts invasive colorectal cancer.
BACKGROUND
The diagnosis of invasive malignancy on biopsies from colorectal neoplasms can be challenging. The concept of intramucosal carcinoma as an indicator of invasive malignancy is somewhat controversial within histopathology circles despite current World Health Organization (WHO) definitions. This study was designed to correlate the biopsy finding of intramucosal carcinoma with the pathology findings after formal surgical excision.


METHODS
We evaluated 89 patients whose initial forceps biopsy contained only intramucosal carcinoma. All tumors were subsequently resected and subjected to formal pathology assessment.


RESULTS
Of 89 patients, 97% were shown to have frankly invasive adenocarcinoma by the current WHO definition. The positive predictive value of intramucosal carcinoma at biopsy for invasive cancer was 96.6%


CONCLUSIONS
This study indicated that there should be a greater willingness among colorectal pathologists to accept the biopsy finding of intramucosal carcinoma as the earlier form of invasive malignancy. Clinicians should alter their treatment algorithms accordingly.
MacDonald
Alastair W
AW
Department of Pathology, Castle Hill Hospital, Cottingham, Hull, UK.
Tayyab
Muhammad
M
Arsalani-Zadeh
Reza
R
Hartley
John E
JE
Monson
John R T
JR
D000230:Adenocarcinoma / Q000175:diagnosis*; D001706:Biopsy; D016022:Case-Control Studies; D003106:Colon / Q000473:pathology; D015179:Colorectal Neoplasms / Q000175:diagnosis*; D006801:Humans; D007413:Intestinal Mucosa / Q000473:pathology*; D008207:Lymphatic Metastasis; D009361:Neoplasm Invasiveness; D009367:Neoplasm Staging; D011379:Prognosis; D011446:Prospective Studies; D012007:Rectum / Q000473:pathology