[Malignant tumors or the small intestine. Review of the literature and report of a clinical case].
The authors present one case of patients with adenocarcinoma of the small bowel. Primary malignant tumors of the small intestine are uncommon neoplasms accounting for 1-2 per cent of all gastrointestinal malignancies. Patients are usually seen late in the course of their illness when curative therapy is unlikely. The rarity of these neoplasms explains in part why the early signs and symptoms frequently go unrecognized and is undoubtedly a major factor contributing to their poor prognosis. Despite a fourfold greater length and a nearly tenfold greater mucosal surface area, the incidence of adenocarcinoma of the small intestine is about a fortieth that of the colon. This relative immunity of the small bowel to the development of the malignant tumors is unexplainable. Several theories have been suggested and include the following: a) the rapid transit time of the small intestine may reduce its exposure to dietary carcinogens; b) the relative sterility of the small intestine compared with the colon may lessen the formation of carcinogenic substances by the action of bacteria on components of bile or other substances within the intestinal lumen; c) certain mucosal enzymes such as benzopyrene hydroxylase that detoxify potential carcinogens are present in higher concentrations in the small intestine than in the colon; d) immunoglobulin A which is found in high concentrations in the small bowel, may protect it against carcinogenic viruses. Interestingly, patients deficient in IgA and those receiving immunosuppressive therapy have been found to have a higher incidence of small intestinal cancer. Adenocarcinoma is the most common primary malignant small bowel neoplasm.(ABSTRACT TRUNCATED AT 250 WORDS)
Pastore
C
C
III Divisione Chirurgica, Ospedale Regionale di Treviso.
D'Annibale
A
A
Fregonese
D
D
Conte
C
C
Pignata
G
G
Mora
G
G
D000230:Adenocarcinoma / Q000601:surgery*; D006801:Humans; D007078:Ileal Neoplasms / Q000601:surgery*; D008297:Male; D008875:Middle Aged
Tumori maligni del tenue. Revisione della letteratura e presentazione di un caso clinico.