MRI of Peliosis Hepatis: A Case Series Presentation With a 2022 Systematic Literature Update

Background Peliosis hepatis (PH) is a rare benign condition, characterized by hepatic sinusoidal dilatation and blood-filled cystic cavities, often found incidentally, with still challenging diagnosis by imaging due to polymorphic appearance.Purpose Based on a retrospective analysis of our series (12 patients) and systematic literature review (1990-2022), to organize data about PH and identify features to improve characterization.Study Type Retrospective case series and systematic review.Population Twelve patients (mean age 48 years, 55% female) with pathology-proven PH and 49 patients (mean age 52 years, 67% female) identified in 33 studies from the literature (1990-2022).Field Strength/Sequence 1,5-T; T1-weighted (T1W), T2-weighted (T2W), diffusion-weighted (DW), contrast-enhanced (CE) T1W imaging.Assessment We compared our series and literature data in terms of demographic (gender/age/ethnicity), clinical characteristics (symptoms/physical examination/liver test), associated conditions (malignancies/infectious/hematologic/genetic or chronic disorders/drugs or toxic exposure) percentage. On magnetic resonance imaging lesion numbers/shape/mean maximum diameter/location/mass effect/signal intensity were compared. PH pathological type/proposed imaging diagnosis/patient follow-up were also considered.Statistical Tests Joanna Briggs Institute (JBI) Critical Appraisal Checklist for Case Reports/Series quality assessment. Intraclass correlation and Cohen's kappa coefficients for levels of inter/intrareader agreement in our experience.Results Patients were mainly asymptomatic (92% vs. 70% in our study and literature) with associated conditions (83% vs. 80%). Lesions showed homogeneous T1W-hypointensity (58% vs. 65%) and T2W-hyperintensity (58% vs. 66%). Heterogeneous nonspecific (25% vs. 51%), centrifugal (34% vs. 8%), or rim-like centripetal (25% vs. 23%) patterns of enhancement were most frequent, with hypointensity on the hepatobiliary phase (HBP), without restricted diffusivity. Good inter- and intrareader agreement was observed in our experience. Concerning JBI Checklist, 19 out of 31 case reports met at least 7 out of 8 criteria, whereas 2 case series fulfilled 5 and 6 out of 10 items respectively.Data Conclusion A homogeneous, not well-demarcated T1W-hypointense and T2W-hyperintense mass, with heterogeneous nonspecific or rim-like centripetal or centrifugal pattern of enhancement, and hypointensity on HBP, may be helpful for PH diagnosis. Among associated conditions, malignancies and drug exposures were the most frequent.