Prevalence of HNPCC in a series of consecutive patients on the first endoscopic diagnosis of colorectal cancer: a multicenter study. The Italian Collaborative Group.

BACKGROUND AND STUDY AIMS: It is difficult to measure the prevalence of hereditary non-polyposis colorectal cancer (HNPCC) in geographical areas that do not have tumor registers, as is the case in the present study, and it was therefore decided to assess the prevalence in Italy using different methods. PATIENTS AND METHODS: The pedigree was established for 485 of 501 colorectal cancer patients diagnosed with colorectal carcinomas. Patients were included consecutively in 13 gastroenterology centers; they had not taken part in prevention examinations. Information was collected regarding the neoplastic pathology observed in the families, confirmed in 90% of cases among 3515 first-degree relatives and in 79.5% of cases among 7068 second-degree relatives. RESULTS: In the 3515 first-degree relatives (1002 parents, 1560 siblings and 953 children), 61 colorectal carcinomas, 29 carcinomas in the digestive tract outside the colon, and 99 carcinomas in other locations were reported. Only five of the 485 patients (1%) satisfied the Amsterdam criteria (three cancers, two of which were in first-degree relatives in different generations and one in a relative younger than 50). When broadening the criteria that we are proposing (satisfying only two of the three Amsterdam criteria), the prevalence would increase to 3% (15 cases). CONCLUSIONS: Modifying the criteria makes it easier to identify new mutations or confirm the existence of those already known, as well as allowing preventative treatment in relatives who are apparently healthy.

Computed tomographic and magnetic resonance imaging of chronic odontoid fractures.

STUDY DESIGN: The analysis of the imaging characteristics found in chronic odontoid fractures. OBJECTIVES: To determine the efficacy of computed tomography and magnetic resonance imaging in diagnosing a chronic odontoid fracture. SUMMARY OF BACKGROUND DATA: Radiographic examination of the cervical spine is intrinsic to the evaluation of all patients with blunt trauma. Injury to the craniocervical junction constitutes 19-25% of all cervical spine fractures. At the authors' trauma center computed tomography is routinely used instead of the open-mouth odontoid radiograph to facilitate cervical spine evaluation. This practice has increased the detection of fractures that are unrecognized in plain radiography, and has, at the same time, raised questions about the age and significance of these fractures. METHODS: Radiography, computed tomography, and magnetic resonance imaging studies were performed on three patients who came to the emergency department with odontoid fractures. Two patients had a history of severe trauma, and one had a history inconsistent with an acute odontoid fracture. One patient also had a technetium Tc 99m methylene dihydroxyphosphonate bone scan. The studies were obtained to determine the age of the fractures. RESULTS: All three patients were determined to have chronic odontoid fractures. This diagnosis was facilitated by the use of computed tomographic and magnetic resonance imaging. Computed tomography showed increased sclerosis in the proximal fracture fragment in all cases and well-corticated fracture edges in one patient. Magnetic resonance images showed normal bone marrow or bone sclerosis in the odontoid process. Soft tissue edema was absent. A bone scan was not useful in resolving this issue. CONCLUSION: Computed tomography and magnetic resonance imaging can be useful in determining the chronicity of an odontoid fracture.