Hepatic amyloidosis: morphologic spectrum of histopathological changes in AA and nonAA amyloidosis.

In hepatic amyloidosis (HA), the relationships between the pattern and extent of amyloid deposition, morphologic changes, associated diseases and clinical data have not yet been demonstrated. In this study, we sought the correlation between the above mentioned parameters in HA. Liver biopsies of 34 HA were retrospectively analyzed for the type, distribution, and intensity of amyloid deposition and associated morphologic changes. AA and nonAA types were classified on the basis of immunohistochemistry. Follow-up clinical and laboratory findings were reviewed. Twenty-three out of 34 patients (67.6%) had AA, and 11 out of 34 patients (32.4%) had nonAA amyloidosis. The predominant localization pattern in AA amyloidosis was vascular (91.3%), and in nonAA amyloidosis it was mixed with other patterns (72.7%). We confirmed that nonAA amyloid involves the hepatic artery, as well as the portal and central vein, but deposition occurred more frequently in the sinusoidal areas. We detected a portal stromal pattern only in cases of nonAA amyloidosis with a mixed pattern of amyloid deposition. The pattern of amyloid deposition in liver differs between the AA and nonAA type amyloidosis. The distribution of amyloid within the liver is not a reliable method for distinguishing AA from nonAA amyloidosis. However, the histological pattern provides strong clues as to the etiology of the amyloid deposits, and could provide information on the clinical status and prognosis of these patients.