We assessed the value of liver biopsy in the diagnosis of fever of unk
nown origin (FUO) in hospital-based patients by a retrospective analys
is of all cases (24 cases) seen at the University of Michigan Medical
Center over a 5-year period. Based on the findings of a liver biopsy p
erformed in the course of the evaluation of FUO, patients were divided
into two groups: a diagnostic group, in which an abnormal liver biops
y was helpful in determining the cause of the FUO, and a nondiagnostic
group, which included those who had either normal biopsy results or a
bnormal biopsy results that did not lead to a final diagnosis. Four pa
tients (16.7%) had diagnostic liver biopsy results (histoplasmosis in
three and tuberculosis in one). Physical findings, such as hepatomegal
y, and laboratory data, including routine liver chemistries, were not
predictive of a diagnostic liver biopsy. Therefore, despite advances i
n diagnostic technology since this subject was last reviewed, liver bi
opsy continues to be useful in the diagnosis of FUO. Furthermore, in e
ndemic or borderline endemic areas, histoplasmosis should be considere
d in the differential diagnosis of FUO, and liver biopsy can be helpfu
l to confirm this diagnosis.