Renal involvement in patients with autoimmune pancreatitis: Ultrasound findings

Objective: The purpose of our study was to retrospectively evaluate the ultrasound findings of renal involvement in patients with autoimmune pancreatitis. Methods: 15 patients with autoimmune pancreatitis (15 male, 0 female, mean age 66 years old, range 44-85) who had renal involvement documented on CT or MR and had abdominal ultrasound within 1 month were included. Ultrasound images were retrospectively reviewed for presence or absence of renal involvement. Shape and echogenicity of the renal lesions were recorded. Results: In 8 out of 15 patients, at least one renal lesion was identified on ultrasound with a total of 9 kidneys. In 7 kidneys, lesions appeared as ill-defined, non-mass like areas of decreased echogenicity. Three lesions showed associated irregular lobular thickening of the renal parenchyma with bulging contour and 1 showed focal area of parenchymal loss. In 2 kidneys, the lesions were seen as solitary or multiple hypoechoic mass-like areas. Ill-defined, non-mass like lesions on ultrasound corresponded to well-circumscribed wedge-shaped lesions in all but one case on CT or MR. Mass-like lesions on ultrasound corresponded to well-circumscribed round lesions on CT or MR. Conclusion: Most common ultrasound findings of renal involvement in patients with autoimmune pancreatitis were ill-defined area of decreased echogenicity.