The diagnosis of adenocarcinoma is made when there is involvement of the muscularis mucosae with invasion of the submucosa. Lesions morphologically resembling adenocarcinoma but confined within the glandular basement membrane (carcinoma in situ) or infiltrating the lamina propria (intramucosal carcinoma) have almost no metastatic potential. For these lesions the term "intraepithelial neoplasia" should be used.
Full thickness muscular invasion with extramural extension has been reported to influence prognosis (Fig. 2a, b): an extramural extension greater than 5 mm has been shown to be the critical point associated with adverse outcome in most studies .
Serosal penetration has been demonstrated to be an independent prognostic variable with a strong negative impact on prognosis (Fig. 2c) [33,34]. It has been shown that the frequency of distant metastases is higher in cases with perforation of the visceral peritoneum compared to cases with direct invasion of adjacent organs or structures without perforation of the visceral peritoneum (occurring in about 50% and 30% of cases, respectively). Furthermore, the median survival time following surgical curative resections has been shown to be shorter. Shepherd has suggested that the prognostic power of local peritoneal involvement in curative resections may supersede that of either local extent of tumour or regional lymph node status .
Fig. 2a-c. Extent of invasion. a Intramural extension. b Extramural extension. c Serosal invasion
Was this article helpful?