Immunoblastic sarcoma after thymus epithelial graft in an immunodeficient child.

A 3 1/2-year-old girl with severe combined immunodeficiency received a thymus epithelial graft. After transient clinical and in vitro immunologic improvement, she developed fever, lung infiltrates and, terminally, massive gastrointestinal bleeding only 2 1/2 months after transplantation. Autopsy revealed widespread immunoblastic sarcoma involving both transplantation sites in the mesentery and thigh, lymph nodes, lung, liver, spleen and gastrointestinal tract. This B cell lymphoma was likely induced by the grafted thymus epithelium.