53 - Burkitt's lymphoma

Summary

Introduction

Burkitt's lymphoma (BL) forms a distinct clinico-pathological entity among the non-Hodgkin's lymphomas. It is particularly frequent in children in tropical Africa and New Guinea, but outside these endemic areas the tumor is rare.

Histology, classification and diagnosis

Although BL was originally described as a clinical syndrome in African children by Burkitt (1958), the most reliable criteria for diagnosis have been its cytological and histological features. Clinically, involvement of the jaw and abdominal viscera are highly characteristic but are not specific. Histologically, it is classified as a non-Hodgkin's lymphoma of undifferentiated type. The ‘starry sky’ pattern given by histiocytes interspersed among malignant lymphoid cells is considered as a highly characteristic but non-specific feature. Cytologic imprints of the tumor show malignant lymphoid cells with deeply basophilic cytoplasm and lipoid vacuoles.

Descriptive epidemiology

Incidence and time trends

The highest incidence rates (5–10) are found in tropical Africa and in Papua New Guinea (see Table 58.4). Significant space-time and seasonal clustering of BL cases has been observed in some areas of Africa but not in others (Morrow, 1982). Elsewhere, the incidence is very low (0.1) (Parkin et al., 1985). Tumors of the jaw are more frequently seen in African children while abdominal tumors are commoner in low-risk areas.

Age and sex distribution

The age distribution of BL in endemic areas is fairly characteristic with a peak incidence at 5–8 years of age but it is rare before age two and after adolescence. In most series, the BL rates are two-fold higher in boys than in girls.