A Rare Case of “Periportal Cuffing” as an Incidental Finding on ¹⁸F-FDG PET/CT

Abstract

A 7-year-old boy with known diagnosis of hereditary spherocytosis and ulcerative colitis was referred for ¹⁸F-fluorodeoxyglucose (¹⁸F-FDG) positron emission tomography/computed tomography after detection of a 28 mm lesion suspicious for malignancy in spleen on upper abdomen magnetic resonance imaging (MRI). As an incidental finding, a moderately increased uptake of ¹⁸F-FDG was observed in periportal region with no definable mass. MRI revealed compatible findings with “periportal cuffing” as described on ultrasonography.

Figure 1.

A 7-year-old boy with known diagnosis of hereditary spherocytosis and ulcerative colitis was referred for ¹⁸F-fluorodeoxyglucose (¹⁸F-FDG) positron emission tomography/computed tomography (PET/CT) after detection of a 28 mm lesion in spleen on upper abdomen magnetic resonance imaging (MRI). The lesion was hypointense on all MRI sequences and no pathological ¹⁸F-FDG uptake was detected in PET/CT. Also, there was increased uptake localized to the right colon segment can be observed on MIP (A) in the right lower quadrant of abdomen (black arrow) which could be associated with ulcerative colitis. However, as an incidental finding, a moderately increased uptake (blue arrows) of ¹⁸F-FDG was observed in periportal region on MIP (A) and transaxial (B, C, D) images with no definable mass. On the light of the ¹⁸F-FDG PET/CT, retrospective evaluation of previous MRI revealed periportal hyperintensity (red arrows) on T2-weighted images (F, I) compatible with “periportal cuffing” as described on ultrasonography. Dynamic contrast-enhanced imaging (G, H, J, K) showed a progressive contrast enhancement (green arrow) in periportal area. Extrahepatic biliary system was normal and magnetic resonance cholangiopancreatography findings were negative for the primary sclerosing cholangitis. On fusion images of PET/CT and T2-weighted images (E) it can be clearly seen that increased ¹⁸F-FDG uptake on periportal region corresponds to periportal hyperintensity on MRI.

Ulcerative colitis is a chronic inflammatory disease of bowel and is characterized by mucosal inflammation of colon and rectum (1). Also, it is known that ulcerative colitis is associated with primary sclerosing cholangitis and pericholangitis (2,3,4). Echo-rich periportal cuffing (ErPC) is a rare ultrasonographic finding which can be seen in patients with hepatitis, inflammatory bowel diseases (IBD) and liver transplants. It is theorized that ErPC is caused by lymphatic fluid obstructing periportal tissue but also can be a result of inflammation of periportal zones in patients with IBD (5,6). IBD can also cause aberrant cell migration from the intestinal mucosa into the portal system via enterohepatic circulation, which can result in hyperechogenic periportal cuffing (5,6). It is known that inflammatory and infectious pathologies can be imaged with ¹⁸F-FDG PET/CT. Also, in literature there are studies that suggest ¹⁸F-FDG PET/CT can be used for assessing disease activity in IBD (7,8,9,10). Even though there are multiple reports of ¹⁸F-FDG PET/CT in IBD, to the best of our knowledge, there is no report of periportal cuffing associated with increased ¹⁸F-FDG uptake in literature and it is not defined in benign conditions that exhibits increased ¹⁸F-FDG uptake (11).