Abstract:
Background:
HIV-associated Kaposi sarcoma (KS) is one of the
most common malignancies in sub-Saharan Africa. The diagnosis
is often based on clinical suspicion, without histopathologic
con
fi
rmation. When biopsies are performed, the accuracy of
interpretation by local pathologists is poorly understood. We
assessed the accuracy of clinical suspicion and pathologic diagno-
sis of KS in 2 East African countries.
Methods:
At 2 large HIV care sites in Uganda and Kenya, we
evaluated consecutive biopsies performed from October 2008 to
January 2013 on HIV-infected adults with clinically suspected KS.
Biopsies were interpreted by both local African pathologists and
a group of US-based dermatopathologists from a high volume
medical center. For the purpose of this analysis, the US-based
dermatopathologist interpretation was used as the gold standard.
Positive predictive value was used to characterize accuracy of local
African clinical suspicion of KS, and concordance, sensitivity,
and speci
fi
city were used to characterize accuracy of local
pathologic diagnosis.Results:
Among 1106 biopsies, the positive predictive value of
clinical suspicion of KS was 77% (95% con
fi
dence interval: 74% to
79%). When KS was not histopathologically diagnosed, clinically
banal conditions were found in 35%, medically signi
fi
cant disorders
which required different therapy in 59% and life-threatening diseases
in 6%. Concordance between African pathologists and US-based
dermatopathologists was 69% (95% con
fi
dence interval: 66% to
72%). Sensitivity and speci
fi
city of African pathologic diagnoses
were 68% and 89%, respectively.
Conclusions:
Among East African HIV-infected patients, we
found suboptimal positive predictive value of clinical suspicion of
KS and speci
fi
c, but not sensitive, histopathologic interpretation. The
fi
ndings call for abandonment of isolated clinical diagnosis of KS in
the region and augmentation of local dermatopathologic services