Hematopathology Case Studies


CASE 7: Burkitt lymphoma


Clinical History:

A 39-year-old man is known to be HIV positive and has had bouts of Pneumocystis carinii (jirovecii) pneumonia in the past two years. He was recently diagnosed with cytomegalovirus retinitis. He has been on highly active anti-retorviral therapy (HAART) that included zidovudine (AZT) for one year, but had to stop. He has experienced worsening abdominal pain for the past 2 days. On physical examination he has diffuse abdominal tenderness, abdominal distension without a fluid wave, and diminished bowel sounds. A plain film radiograph of the abdomen shows no free air, but there are dilated loops of bowel with air-fluid levels. An abdominal CT scan shows several 1 to 3 cm masses involving distal small bowel. A laparotomy is performed and a 20 cm segment of ileum is resected.
  1. What is the predominant cell type in this mass lesion?

    2. There are large lymphocytes with nuclei having clumped chromatin.

  2. What is the diagnosis and how does this relate to his history?

    3. This is a high-grade B-cell lymphoma, a Burkitt-like lymphoma, that is typical of one kind of high grade lymphoma (the other is diffuse large B-cell lymphoma) seen with HIV infection and AIDS. This is the "sporadic" form of Burkitt lymphoma that typically involves the abdomen. The classic "endemic" form of Burkitt lymphoma mainly affects children and young adults, presents as an extranodal mass involving the mandible, often involves kidneys, ovaries, and adrenals and has a characteristic karyotype with t(8:14). The overall prognosis following chemotherapy is better for children.

  3. What would a peripheral lymphocyte count (with subsets) probably demonstrate?

    4. He would have a lymphopenia and a CD4 lymphocyte count probably under 200/microliter. His HIV-1 RNA level would likely be elevated.

  4. Why did he have to stop the zidovudine?

    5. Zidovudine (AZT) suppresses bone marrow, and he probably had severe pancytopenia.