Y. Ninomiya et al., Unrecognizable intramucosal spread of diffuse-type mucosal gastric carcinomas of less than 20 mm in size, ENDOSCOPY, 32(8), 2000, pp. 604-608
Background: Diffuse-type intramucosal gastric carcinomas sometimes spread w
ithin the mucosa beyond their macroscopic margins, often causing positive r
esection margins upon local resections such as endoscopic mucosal resection
.
Patients and Methods: A consecutive series of 34 patients with solitary, sm
all (less than 20 mm in diameter macroscopically). and macroscopically well
demarcated diffuse-type mucosal carcinomas, who were treated with gastrect
omy followed by detailed pathological examination, were included in the pre
sent study. Unrecognizable intramucosal spread is defined as an area of can
cer which is indistinguishable macroscopically from its peripheral noncance
rous area, and covered by normal epithelium with neither morphologic nor co
lor changes. We examined the extent of unrecognizable intramucosal spread,
measuring the maximum distances between macroscopic and microscopic margins
on the sections, and investigated its relationship with four factors: loca
tion of the lesion, macroscopic size, histologic ulcer formation, and degre
e of atrophy of the background mucosa.
Results: The maximum distance between macroscopic and microscopic margins w
as significantly larger (maximum 10 mm) in the background mucosas with mark
ed atrophy than in those with little or no atrophy: No other factors, inclu
ding location, macroscopic size and ulcer formation, correlated with it.
Conclusion: We should pay particular attention to unrecognizable intramucos
al spread, especially in markedly atrophied mucosa, when treating small dif
fuse-type mucosal gastric cancer by local resections such as endoscopic muc
osal resection. In addition, because of unrecognizable intramucosal spread,
a surgical incision margin of at least 10 mm from the macroscopic margin i
s indicated.