Incidental cancer in colectomy specimens from patients with familial adenomatous polyposis: single centre experience and literature review

Background Since cancer development is inevitable in patients with familial adenomatous polyposis (FAP), we aimed to determine the incidence of incidental malignancy in prophylactic colectomy specimens. Methods The files of patients who underwent prophylactic surgery for FAP between 2010 and 2020 were retrospectively reviewed. The incidence of incidental malignancy in histopathological specimens was examined and a comprehensive literature review was made. Results Fifty-five patients were included in the study, of whom 30 patients had a diagnosis of primary malignancy. Prophylactic colectomy was performed on 25 patients. The pathology results indicated that the specimens were benign in 12 patients (48%) and revealed carcinoma in situ in 11 patients (44%). Incidental malignancy was detected in 2 patients (8%). In the literature review, there were 243 patients who underwent prophylactic colectomy and incidental cancer was detected in 25 patients (10.3%) with the stages of 1 (7.4%), 2 (2.1%), and 3 (0.8%), respectively. Conclusions Incidental cancer is not rare in patients who have undergone prophylactic colectomy for FAP. Hopefully. they are usually at early stages and unexpected advanced cancers are seen rarely.