All patients receiving surgery for an anal fistula in the years 1999 to 2019 at a tertiary university referral hospital were included in the analysis. A retrospective review of patients' charts was performed. Patients suffering from FAAC were eligible for histopathological analysis including immunohistochemistry and molecular profiling.
The fistula-associated anal adenocarcinoma is rare in patients suffering from anal fistulas. There is only little data available for this patient collective making characterization and management of this disease difficult. Late diagnosis and advanced tumor stage at diagnosis result in poor clinical outcome. It is the purpose of this study to evaluate patients clinically diagnosed with a FAAC and to further perform a histopathological characterization of the available tumor specimen.