Angiomatous lymphoid hamartoma: inhibitory effects on erythropoiesis, growth, and primary hemostasis.

An 11-year-old boy was noted to have microcytic anemia, growth retardation, polyclonal hypergammaglobulinemia, and abnormal platelet function. An angiomatous lymphoid hamartoma was removed from the retroperitoneal space. Postoperatively the child exhibited a dramatic growth spurt and complete resolution of the abnormal laboratory measurements. Studies were performed before and after tumor removal to investigate the nature of the associated anemia, growth retardation, and altered hemostasis. There was no evidence of iron deficiency, thalassemia, or an antierythropoietin factor. Prolonged bleeding time and impaired ristocetin-induced platelet aggregation normalized following tumor resection. Serum obtained before surgery inhibited lymphocyte proliferation in mixed lymphocyte culture as well as fibroblast growth in vitro. Detailed study of growth regulatory hormones failed to reveal significant alterations except for significantly reduced somatomedin which normalized after surgery. The factor(s) which inhibit in vitro cellular growth and lower in vivo plasma somatomedin concentration remain unknown.