ABSTRACT
BACKGROUND AND STUDY
AIMS:
We present a case of invasive micropapillary
carcinoma (IMPC) of the
colon treated by endoscopic resection following magnifying
endoscopy. A 47-year-old
woman visited our
hospital for follow-up of a positive
fecal occult blood test.
Colonoscopy revealed a semi-pedunculated reddish
polyp, the surface of which showed gentle irregularity, and mild tension in the
sigmoid colon. Magnifying
colonoscopy with
narrow band imaging revealed an irregular surface pattern with heterogeneity in vascular diameter and distribution. Magnifying endoscopic findings using
crystal violet staining showed an irregular pit pattern with an expansion of stromal areas. Endoscopic resection of the
sigmoid colon tumor was performed, and the
histology of the resected specimen primarily revealed a micropapillary component with a small moderately differentiated
adenocarcinoma component that massively invaded into the submucosal layer, accompanied by lymphatic invasion, although the
tumor was very small (7âmm in diameter, smaller than any in previous
reports).
Laparoscopy-assisted sigmoidectomy and regional
lymph node resection were performed; neither
cancer nor
lymph node metastases were present. This is the first
report of a case with early-stage colonic IMPC observed with magnifying
colonoscopy.