AbstractBackgroundPerianal hidradenitis suppurativa (PHS) is a chronic recurrent inflammatory disease of the apocrine glands present in the skin and soft tissue adjacent to the anus. It is often misdiagnosed or treatment is delayed, resulting in the formation of an abscess or, in the worst case, leading to sepsis. It is difficult to treat perianal lesions merged with fistulae completely due to its high recurrence rate. Therefore, we should diagnose it correctly and treat it with appropriate methods.Presentation of caseWe report two cases of PHS with anal fistulae that were examined preoperatively using magnetic resonance imaging (MRI) and treated safely by surgery without any recurrence.DiscussionThe anal sphincter area cannot be visualized...