Agreement between diagnoses of childhood lymphoma assigned in Uganda and by an international reference laboratory

BACKGROUND Correct diagnosis is key to appropriate treatment of cancer in children. However, diagnostic challenges are common in low-income and middle-income countries. The objective of the present study was to assess the agreement between a clinical diagnosis of childhood non- Hodgkin lymphoma (NHL) assigned in Uganda, a pathological diagnosis assigned in Uganda, and a pathological diagnosis assigned in The Netherlands. METHODS The study included children with suspected NHL referred to the Mulago National Referral Hospital, Kampala, Uganda, between 2004 and 2008. A clinical diagnosis was assigned at the Mulago National Referral Hospital, where tissue samples were also obtained. Hematoxylin and eosin-stained slides were used for histological diagnosis in Uganda, and were re-examined in a pathology laboratory in The Netherlands, where additional pathological, virological and serological testing was also carried out. Agreement between diagnostic sites was compared using kappa statistics. RESULTS Clinical and pathological diagnoses from Uganda and pathological diagnosis from The Netherlands was available for 118 children. The agreement between clinical and pathological diagnoses of NHL assigned in Uganda was 91% (95% confidence interval [CI] 84-95; kappa 0.84; P < 0.001) and in The Netherlands was 49% (95% CI 40-59; kappa 0.04; P = 0.612). When Burkitt's lymphoma was considered separately from other NHL, the agreement between clinical diagnoses in Uganda and pathological diagnoses in Uganda was 69% (95% CI 59-77; kappa 0.56; P < 0.0001), and the corresponding agreement between pathological diagnoses assigned in The Netherlands was 32% (95% CI 24-41; kappa 0.05; P = 0.326). The agreement between all pathological diagnoses assigned in Uganda and The Netherlands was 36% (95% CI 28-46; kappa 0.11; P = 0.046). CONCLUSION Clinical diagnosis of NHL in Uganda has a high probability of error compared with pathological diagnosis in Uganda and in The Netherlands. In addition, agreement on the pathological diagnosis of NHL between Uganda and The Netherlands is very low.