Abstract

Colorectal cancer can have a gross appearance similar to linitis plastica of the stomach. However, most of these cases are not primary colorectal lesions but are, indeed, metastases from other sites. This study was designed to answer the following questions; (1) Why is the linitis plastica of the large intestine so rare compared to that of te stomach? (2) Which part of the large intestine is predominantly affected by linitis plastical form? (3) Is the histogenesis of linitis plastica involving the lagre intestine similar to that involving the stomach? Of the 911 cases of the resected colorectal primary cancer, we found only 4 cases of primary linitis plastica of the intestine (0.4%) and another one case referred from other hospital. All involved the rectum; they were of encircling carcinoma with diffuse transmural infiltration of signet ring cell carcinoma accompanied by marked desmoplasia as in the gastric form. Signet ring cell carcinoma of the large intestine comprised 1.8%(n=16) of the total colorectal cancer(n=911), and predominantly occurred in the rectum(n=8). There was no histologic difference between the linitis plastica in both stomach and colon in terms of desmoplastic reaction, once the tumor infiltrated into the submucosa. We conclude that rarity of signet ring cell carcinoma in the large intestine together with its predominant occurrence in the rectum can explain low incidence of primary colorectal linitis plastica and high preference in the rectum.

• Keywords: Primary linitis plastica;Rectum;Stomach