A 16-yrs-old girl presents with bowel obstruction. Laparotomy reveals markedly enlarged para-aortic lymph nodes. Biopsy of lymph nodes exhibit a diffuse neoplastic infiltrate of small, round lymphocytes with a “starry sky” appearance on low power. The cytoplasm of some of the lymphocytes is vacuolated and fat stains are positive. You would expect the neoplastic cells to demonstrate a:

The patient has Burkitt lymphoma (Lukes-Collins; small non-cleaved), which is the most common malig­nant lymphoma in children. Approximately one third of all childhood lymphomas in the United States are of the Burkitt type. There is an Mrican and a North American variant. The relationship of Burkitt to the Epstein-Barr virus is more secure with the Mrican than the North American variant. The Mrican variant has a predilection for the jaw, while the North Ameri­can variant is more often an abdominal mass, located in the ileocecal region, ovary, or retroperitoneum. The lymph nodes are diffusely involved with monotonous, round, non-cleaved cells with numerous mitoses (very aggressive cancer) punctuated by clear spaces with macrophages containing debris ("tingible" macro­phages) giving the impression of a "starry sky appear­ance," the stars representing the macrophages and the black of night the lymphocytes. The neoplastic B cells have a characteristic t(8;14) translocation where the c-myc oncogene is translocated from chromosome 8 to chromosome 14. Burkitt cells contain vacuoles that contain lipid, which stains positively with oil red O. It is a high grade lymphoma with a predilection for metastasis to the bone marrow and other organs.