Typical MR imaging findings of perianal infections in patients with hematologic malignancies

We aimed to investigate the MR imaging findings of patients with hematologic malignancies who have symptoms suggesting perianal infection and to demonstrate the importance of imaging.

The study included 36 patients with hematologic malignancies who underwent anorectal MR imaging in our department between September 2011-May 2016. Two radiologists experienced in abdominal radiology viewed the MR images in consensus. Abscesses, fistulous or sinus tracts, signal alterations and contrast enhancement in keeping with an inflammation and edema in the perianal region were recorded.

Perianal abscess was found in 16 of the 36 patients. In 10 of these 16 patients there was also extensive inflammatory signal alterations in perianal and/or perineal soft tissues. In six of the 36 patients perianal fistula was detected. A sinus tract was seen at the level of subcutaneous external anal sphincter in one patient. Inflammatory signal alterations in the surrounding soft tissues were present in three of these seven patients. There were abscesses in labium majus in two patients and in one patient there were perineal abscesses with accompanying inflammatory signal alterations. In six of the 36 patients no abscess or fistula/sinus tract was seen. There were only inflammatory signal alterations with contrast enhancement in perianal or subcutaneous tissues. In two patients presenting with perianal pain and hemorrhoids, minimal inflammatory changes were detected on MR images. There were two patients with normal MR imaging findings.

As digital examination of the anorectum and rectoscopy are avoided in neutropenic patients, MR imaging, which clearly demonstrates the perianal pathology should be preferential.