Diagnosis of HIV-related malignancies in resource-constrained settings of sub-Saharan Africa, a cautionary tale for non-Hodgkin’s lymphoma

Background

Non-Hodgkin’s lymphoma (NHL) subgroups, immunophenotypes, and genotypes have been defined in developed countries but how that information translates to resource-constrained sub-Saharan Africa medical settings is undocumented. Local published data on NHL subgroups come largely from retrospective clinical biopsy study sets of paraffin-embedded tissues filed in local pathology archives. Relatively poorer representation of the rural and low socioeconomic populations is likely in such data. Prospectively identified NHL subgroups using immunologic and molecular techniques in consecutive presentations of patients would best clarify NHL subgroups and confounding diagnoses.

Materials and methods

Approximately 456 cases of malignant lymphoma (ML) from both the sub-Saharan African Lymphoma Consortium and Mid-region AIDS and Cancer Specimen Resource (ACSR) projects in East Africa were examined for microscopic morphology and 30 monoclonal antibodies for common NHL antigens; Lana-1 for HHV-8 (immunohistochemical, IHC); in situ hybridization (ISH) for EBV-encoded RNA, kappa/lambda light chains (Ventana, Tucson, AZ); and fluorescent in situ hybridization (FISH) c-myc t(8;14) (Abbott/Vysis, Downer’s Grove, IL).

Results

There was a small but consistent population of other tumors that reduced the accuracy of both the clinical and histopathology diagnosis of NHLs including those given in Table 1.

Table 1 Confounding tumor look-alikes.

Conclusions

Clinical diagnosis of NHL is complicated by other pathological entities that lead to inaccuracies. Histopathology diagnosis based on hematoxylin and eosin (H&E) stained tissue morphology alone improves accuracy (vs. clinical diagnoses alone) but can provide additional inaccuracies due to tumor look-alikes. Caution is warranted in considering either clinical diagnosis or local histopathology diagnosis in a resource-constrained medical setting as accurate in the conduct of clinical treatment trials or epidemiology studies.