CT presentations of colorectal cancer with chronic schistosomiasis: A comparative study with pathological findings.

OBJECTIVE: To clarify pathological basis of computed tomography (CT) presentations of colorectal cancer (CRC) with schistosomiasis for the purpose of improving the accuracy of CT diagnosis and differential diagnosis of the condition.
MATERIALS AND METHODS: 130 patients (87 male and 43 female; age range 49-86 years, mean 71.1) were selected whose diagnoses were pathologically confirmed as CRC with schistosomiasis. All the patients underwent abdominal plain CT and contrast enhanced scanning. The location, morphology, size, calcification features and enhancement modalities (patterns) were evaluated and compared with the pathological findings by two radiologists in a blind way.
RESULTS: CT showed that in 130 patients, the tumors occurred in the large intestine, among which 109 (83.9%) were solitary and 21 (16.1%) were multifocal. The intestinal wall was irregularly thickened in 123 patients, with soft tissue masses in 7 patients. Linear, spotty and small patchy calcifications were seen in 104 (80.0%) patients, with unclear margins in 96 patients. The tumors were markedly unevenly enhanced in 92 patients. Pathological examination revealed adenocarcinoma in 114 patients and in 104 patients, calcified Shistosoma japonicum (S. japonicum) ova inside the tumors, 15 patients were mucinous adenocarcinoma, and one patient was that of adenosquamous carcinoma.
CONCLUSION: Irregular thickening of the intestinal wall, soft tissue masses, multiple S. japonicum ova calcifications inside the tumor with obscured margins and multiple intestinal masses in some patients are important CT features of CRC with schistosomiasis. Published by Elsevier Ireland Ltd.