Langerhans' cell histiocytosis as a cause of periportal abnormal signal intensity on MRI

Abstract

Three cases of hepatic Langerhans' cell histiocytosis (LCH) manifesting as periportal abnormal signal intensity on magnetic resonance images are described. One case also demonstrated intrahepatic bile duct dilatation due to secondary sclerosing cholangitis. Hepatic involvement of LCH could be included in the differential diagnosis of periportal abnormal signal intensity in children.

Case of disseminated Langerhans’ cell histiocytosis presenting with sclerosing cholangitis

“…Hepatic involvement in LCH is well established. The main histopathologic features of hepatic LCH are nonspecific portal triaditis, Langerhans’ cell infiltration, bile duct proliferation, portal fibrosis and biliary cirrhosis 1,4,6 . Early in the course of the disease, the lesions are usually proliferative and locally destructive.…”

“…Liver involvement is common in disseminated LCH with hepatomegaly observed in up to 60% of patients. Hepatic disfunction characterized by pruritis, cholestasis and portal hypertension is unusual at the time of diagnosis, but may be present or develop somewhat later on 1,5,6 . Liver pathology in LCH is also variable, changing from Langerhans’ cell infiltration in the portal area and/or bile duct to fibrosis, cirrhosis and periductal sclerosis simulating sclerosing cholangitis 4 .…”

Extra-osseous involvement of Langerhans? cell histiocytosis in children

“…Histologically, hepatic involvement by LCH is characterised by periportal histiocytic infiltration evolving in four phases: from an initial proliferative phase to a granulomatous, xanthomatous and finally to a fibrous phase [46,47]. Hepatomegaly and the different stages can be well depicted on US, CT and MRI [5, 45,48,49,50]. Periportal hypoechoic changes correspond to hypodensities on CT and to moderate-to-high intensities on T2-W MRI, reflecting the proliferative and granuloma- Fig.…”

“…Subsequent change to hyperechoic nodules, which are composed of fat, occurs as a result of evolution into the xanthomatous phase. They remain hypodense on CT, while on MRI this stage is characterised by hyperintensities on T1-W images, being hypointense on T2-W images [49,50,51]. Finally, micronodular biliary cirrhosis results from extensive periductal and periductular fibrosis associated with sclerosing cholangitis [45,46].…”

Abdominal manifestations of histiocytic disorders in adults: imaging perspective

“…6 Abnormal periportal signal on T 2 weighted MR images can also be seen with MR and may appear as hypoechoic on ultrasound. 7 It is believed that infiltration by histiocytes accounts for the abnormal periportal abnormality. Hepatic nodules appear hyperechoic on sonography, show low attenuation on CT and may show signal loss on Gradient Recalled Echo (GRE) T 1 weighted out-of phase images, indicating the presence of microscopic fat (Figure 2a,b).…”