Pilonidal sinus of the perianal region: Difficult to diagnose

BACKGROUND: Pilonidal sinus usually arises in the area of natal cleft in young men. Hair accumulation in the wound in the perianal region is very rare. Although pelvic magnetic resonance imaging (MRI) is used in the differential diagnosis of perianal region diseases, it is not possible to diagnose perianal pilonidal sinus by MRI. CASE: A 24-year-old male patient presented with the complaint of swelling and itching in the anus for several months. On physical examination, the area giving endure and fluctuation was detected in the perianal region. An area of ​​2 × 2 cm hyperintense in T2 was seen in pelvic MRI. In the surgical exploration, collection of hair was seen at 7 o’clock at perianal region with pus discharge. After the cavity was cleaned, crystallized phenol was applied to the area and the wound was left to secondary healing. Granulation was observed after 4 weeks. CONCLUSION: Perianal pilonidal sinus is very rare in the literature and is often confused with other perianal diseases such as perianal abscess or anal fistula. In this respect, when examining perianal diseases, especially in young men, perianal pilonidal sinus should be kept in mind in the differential diagnosis.