HIV infection and c-MYC status in endemic Burkitt lymphoma

Accuracy of Burkitt lymphoma diagnosis in constrained pathology settings: importance to epidemiology

CONTEXT

Burkitt lymphoma (BL) is endemic in Uganda and because of the high incidence, diagnosis is often presumed during clinical care and epidemiologic studies.

OBJECTIVES

To assess the accuracy of the clinical and the local pathology diagnosis of BL as assessed by an outside pathology review diagnosis and to understand the limitations on histopathology practice in a resource-constrained setting at 1 hospital in Uganda.

DESIGN

Clinically presumed pediatric (<15 years) BL cases with biopsies and pathology reports, from 1993 to 2007, were identified at St Mary's Hospital, Lacor (Gulu, Uganda). Local histopathology procedures, hematoxylin-eosin-stained tissue sections, and formalin-fixed paraffin-embedded blocks were reviewed onsite by an outside pathologist, followed by outside study that included tissue microarray immunohistochemistry and in situ hybridization.

RESULTS

Local pathology laboratory procedures were inconsistent and suboptimal, especially for tissue fixation. There were 88 clinically presumed BL cases. Sixty-three could be reviewed by outside pathology (25 cases of lost blocks or no remaining tumor) and showed a clinical diagnostic accuracy of 75% (47 confirmed of 63), with a possible range of 62% to 85%, depending on the actual diagnosis of the 25 nonevaluable cases. There were 64 BL cases diagnosed by local pathology. Forty-five could be reviewed by outside pathology (19 cases of lost blocks or no remaining tumor) and showed a local pathology diagnostic accuracy of 82% (37 confirmed of 45), with a possible range of 58% to 88%, depending on the actual diagnosis of the 19 nonevaluable cases. Non-BL diagnoses included other non-Hodgkin lymphomas, Hodgkin lymphoma, and benign infectious lymphadenopathy.

CONCLUSIONS

Accuracy of clinical diagnosis of BL was reduced by inclusion of other diseases with similar clinical presentations. Local pathology, using morphology alone, only marginally improved clinical accuracy and often could not support outside pathology review due to inadequate laboratory procedures. There is an urgent need to improve pathology services in Uganda before conducting high-quality clinical and epidemiologic studies.