Table 2

Characteristics of patients with hyperplastic polyposis syndrome (HPS) in which an interval carcinoma was detected

PatientAgeSexNumber of endoscopies until CRCLocation CRCSize CRC (TNM)Immediate adjacent polypsTime (months) between HPS diagnosis and CRC detectionTime (months) between last endoscopy and diagnosis CRCMost proximal intubation point last endoscopyAbnormalities and treatment during last endoscopy before diagnosis CRC
149M2Ascending colon16 mm (T3N0M0)SA11.47.7Caecum>20 polyps which were only diagnostically biopsied.
267F3Ascending colon95 mm (T3N0M0)None80.444.2Transverse colonMultiple polyps throughout the colorectum. Procedure complicated by perforation (aborted). Multiple polyps remained in situ. Patient returned with symptoms after 44.2 months.
358M4Rectum4 mm (TisN0M0)HP36.411.6Sigmoid (subtotal colectomy)All visible rectosigmoidal polyps removed.
448M2Transverse colon10 mm (T1N0M0)HP4.34.3CaecumMultiple polyps detected, of which 11 polyps were removed. Multiple polyps remained in situ
548F3Descending colonNot stated (TisN0M0)HP15.610.1CaecumMultiple polyps throughout the colorectum, which were only diagnostically biopsied
  • CRC, colorectal cancer; HP, hyperplastic polyp; SA, serrated adenoma.