CT in patients with scirrhous carcinoma of the GI tract: imaging findings and value for tumor detection and staging.

OBJECTIVE

The purposes of this study were to analyze the CT features of scirrhous carcinoma of the gastrointestinal (GI) tract and to assess the usefulness of CT in detecting and staging these lesions.

MATERIAL AND METHODS

This is a retrospective evaluation of 31 proven cases of scirrhous carcinoma (linitis plastica) of the GI tract imaged in our institution from 1986 to 1994. Twenty-two patients had primary gastric carcinoma, and nine had carcinoma of the colon (rectosigmoid in eight and right colon in one). CT examinations were reviewed and correlated with pathologic and/or surgical findings in all patients and with barium examinations in 19 cases. A modified Dukes classification was used to stage these lesions without knowledge of the pathologic and surgical results.

RESULTS

Four gastric lesions were missed during the initial CT examination. Seventeen patients had extensive circumferential lesions, and five had focal plaquelike lesions. The wall thickness ranged from 1 to 3 cm (mean, 1.8 cm). Homogeneous enhancement was seen in 17 patients, slightly heterogeneous enhancement was seen in one, a target configuration was present in two patients, and intramural calcification was present in one patient. All colonic lesions were circumferential, homogeneously enhancing with a wall thickness ranging from 1 to 3 cm (mean, 2 cm). CT scans showed limitations in evaluating local parameters. Compared with surgical and pathologic staging, CT correctly staged 26 patients, understaged four patients, and overstaged one patient. Among the 19 patients with pathologically proven stage D lesions (61%), CT correctly staged 17 patients (89%) and had a 100% positive predictive value. One case of hepatic metastases, 13 cases of malignant ascites, and 11 cases of omental and peritoneal metastases were found.

CONCLUSION

CT is an important complimentary imaging technique to detect scirrhous carcinoma. The sensitivity of detection depends on the size of the lesion and the quality of the examination. CT has limitations in staging early lesions but shows a high sensitivity (89%) in detecting Dukes stage D lesions. Accurate CT staging in these individuals (61% in this series) allows a more adequate treatment strategy and avoids unnecessary exploratory laparotomies.