title: Large regenerative nodule perfused by the portal vein.
abstract: In a 42-year-old Japanese woman with esophageal varices, abdominal ultrasound (US) demonstrated a hyperechoic lesion 3 cm in diameter in segment 4 (S4). This nodular lesion had high intensity on T1-weighted magnetic resonance imaging (MRI), low intensity on T2, and very high intensity on superparamagnetic iron oxide (SPIO) enhanced MRI. Angiography showed sparse distribution of arterial branches and dense distribution of portal branches in S4. Meandering, thin arteries were seen in the peripheral area of the right lobe. The second branches of the portal vein were hardly visualized anywhere in the liver. Computed tomography arterioportography (CTAP) revealed portal blood flow dominance in this nodular lesion. There was no evidence of ischemic liver damage, such as thromboembolic episodes, laboratory data of liver damage, coagulation abnormalities etc. Therefore this abnormality was more likely to be caused by anomalous changes than thrombotic changes. Needle biopsy revealed no atypical cells. Two years later, the nodule size was reduced to 1.9 cm, showing its benign nature. Based on these findings, this lesion was classified as a new type of large regenerative nodule (LRN) associated with anomalies in the portal veins and arteries. This is the first report of an LRN of this size in which portal vein perfusion was dominant. Moreover, this lesion was difficult to differentiate from hepatocellular carcinoma (HCC) by imaging. Analysis of the images and pathological features of this case would contribute to a better understanding of the pathogenesis of nodular lesions of the liver.
authors.affiliation: Internal Medicine, Chiba Municipal Kaihin Hospital.
authors.forename: Mari
authors.initials: M
authors.lastname: Inada
authors.forename: Kazuhiko
authors.initials: K
authors.lastname: Kita
authors.forename: Fukuo
authors.initials: F
authors.lastname: Kondo
authors.forename: Hirofumi
authors.initials: H
authors.lastname: Saito
authors.forename: Michio
authors.initials: M
authors.lastname: Kimura
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Maruyama
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Fukuda
authors.forename: Masaharu
authors.initials: M
authors.lastname: Yoshikawa
authors.forename: Shoichi
authors.initials: S
authors.lastname: Matsutani
authors.forename: Masaaki
authors.initials: M
authors.lastname: Ebara
authors.forename: Hiromitsu
authors.initials: H
authors.lastname: Saisho
authors.forename: Isamu
authors.initials: I
authors.lastname: Sugano
mesh_terms: D000328:Adult; D000792:Angiography; D006528:Carcinoma, Hepatocellular / Q000175:diagnosis; D000013:Congenital Abnormalities / Q000175:diagnosis; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D008099:Liver / Q000098:blood supply*; D008113:Liver Neoplasms / Q000175:diagnosis; D008115:Liver Regeneration; D008279:Magnetic Resonance Imaging; D011168:Portal System / Q000002:abnormalities; D011169:Portal Vein / Q000002:abnormalities*; D014057:Tomography, X-Ray Computed