HYPERECHOIC PSEUDOTUMORS IN SEGMENT-IV OF THE LIVER

Hypoechoic pseudotumors usually are considered ''spared areas'' in a f atty liver; they frequently are detected at the fourth hepatic segment close to the portal vein. Over a 3 year period, we observed 14 patien ts with a hyperechoic pseudotumor in otherwise normal livers; all of t hese lesions resembled a hypoechoic pseudotumor of the fourth segment with respect to site and morphology. In all cases echographic findings did not significantly change during a follow-up period ranging from 4 to 12 months. Computed tomographic examination was normal in two case s, whereas in the remaining 12 cases the hyperechoic lesion was apprec iable as a hypodense area on both direct and dynamic scans; the contra st enhancement was never typical for a malignancy or a hemangioma. Six patients also underwent a color Doppler and power Doppler examination , which never demonstrated intralesional or perilesional abnormalities in the vascular signals. Three patients, who underwent surgery for ad enocarcinoma of the large bowel, had intraoperative sonography and son ographically guided biopsy; a hepatic steatosis was diagnosed at histo logic examination in all cases. The uniqueness of the cases presented here relies on the finding of focal steatosis at a site where, accordi ng to the most credible hypothesis, intracellular deposition of trigly cerides is less likely because of possible variation of the regional p ortal circulation. From a practical point of view it should be emphasi zed that, in addition to the more frequent hypoechoic pseudolesions, h yperechoic pseudonodular images just anterior to the portal vein can b e observed in normal livers; in our experience these lesions should be interpreted as a focal steatosis in an atypical site.