BURKITT, in 1958, drew attention to the high incidence of an unusual type of lymphoma in Uganda.1 It occurs largely in children and involves the retroperitoneal space, facial bones, and ovaries in females.2 The peripheral lymph nodes are usually spared. These lymphomas are uniformly immature lymphoreticular tumors with prominent histiocytic phagocytosis giving a characteristic microscopic "starry sky" appearance.3 This histiocytic phagocytosis is not restricted to the Burkitt type of lymphoma,4 which is best recognized by its anatomical distribution.
The epidemiology of Burkitt's tumor in Africa5,6 suggests that its incidence is influenced by environmental factors. These include a warm climate throughout the year5 and a heavy annual rainfall.6 Cases have been observed only occasionally at altitudes higher than 5,000 feet.6,7 This may be related to lower prevailing temperatures at higher altitudes. Its geographical distribution has been suggested as evidence that the tumor may be