PT - JOURNAL ARTICLE AU - Rajashri Veeresh Patil AU - Iain Stephenson AU - Cathy J Richards AU - Yvette Griffin TI - Rectal cancer mimic: a rare case of syphilitic proctitis AID - 10.1136/bcr-2020-235522 DP - 2020 Dec 01 TA - BMJ Case Reports PG - e235522 VI - 13 IP - 12 4099 - http://casereports.bmj.com/content/13/12/e235522.short 4100 - http://casereports.bmj.com/content/13/12/e235522.full SO - BMJ Case Reports2020 Dec 01; 13 AB - Syphilitic proctitis is a rare presentation of sexually transmitted infection that poses a diagnostic challenge as it mimics rectal cancer clinically, radiologically and endoscopically. We report a case of a 66-year-old male patient with a background of HIV infection presenting with obstructive bowel symptoms and initial diagnosis of rectal cancer on CT. Sigmoidoscopy and histopathology were non-diagnostic. A diagnosis of secondary syphilis was suspected after obtaining sexual history and diagnostic serology, avoiding planned surgical intervention.