Central nervous system medulloepitheliomas are extremely rare and malignant (World Health Organization Grade IV) primitive neuroectodermal tumors (PNETs) that arise in childhood. Unlike other PNETs, medulloepitheliomas have a dismal prognosis, with only 2 reported cases in the literature in which the patient survived beyond 5 years after treatment. The authors report on the third known case of a child who survived longer than 5 years. A review of all the published cases of medulloepithelioma is also presented, and alternative treatment strategies for PNET tumors, including high-dose chemotherapy with stem-cell rescue, are discussed.

A female neonate with diffuse hemangiomatosis and hepatic hemangiomas had cardiac insufficiency develop and had failure to thrive. Her disease was unresponsive to prednisone. She received two courses of cyclophosphamide 10 days apart and a final course 2.5 weeks later. Twelve days after the second course of cyclophosphamide, her liver was significantly smaller. She is now 6-years-old, well-developed, and has no signs of hepatomegaly, malnourishment, or heart failure. Cyclophosphamide appears to be a safe, effective, and rapid treatment of life-threatening hemangiomas of infancy.

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Peripheral blood stem cells (PBSCs) are being used as an alternative to autologous marrow rescue for hematopoietic reconstitution after high- dose chemotherapy in patients with neuroblastoma and other solid malignancies. Use of PBSCs is preferred by some because of the belief that there is less risk of tumor contamination. Because tumor stem cell contamination is thought to be one contributing cause of relapse after myeloablative therapy and autologous reconstitution, we examined the potential risk of reinfusing circulating neuroblastoma cells by in vitro evaluation of their clonogenicity. Immunocytologic and tumor cell clonogenic analyses were performed on 74 blood samples obtained from 56 children with advanced-stage neuroblastoma. Concurrently drawn bone marrow specimens were evaluated in 30 instances. Circulating neoplastic cells were detected in 19 of 74 (26%) for all specimens and by immunologic techniques (26%). Using a clonogenic assay, 13 grew identifiable tumor colonies. Comparing results with the two techniques showed tumor colony growth in 10 of the 19 positive specimens by immunocytology. However, 3 of 53 samples (6%) that were negative by immunocytology were positive by the clonogenic assay. Of the 11 positive blood samples, 9 concurrent marrows contained neuroblastoma cells; of the 19 negative blood specimens, 3 concurrent marrows had metastatic disease. We conclude that circulating neuroblastoma cells are present in peripheral blood and have clonogenic properties in vitro. This supports the view that tumor cell contamination may well be one cause of relapse after autologous reconstitution. Consequently, PBSC collections should also undergo meticulous monitoring for tumor contamination before autologous reinfusion.

Transient myeloproliferative disease (TMD) is often associated with a trisomy 21 cell line, but it is not always associated with clinical signs of Down syndrome. We report on a phenotypically normal newborn boy who presented with a high white blood cell count, undifferentiated blasts, and cutaneous leukemic infiltrates and compare this patient with the literature on TMD and trisomy 21. Chromosome analysis of bone marrow, and subsequently of skin fibroblasts, documented constitutional mosaicism for trisomy 21. A decrease in the frequency of blast cells paralleled a decrease in cells demonstrating trisomy 21 in hematopoietic tissues, and a complete clinical recovery was seen without the use of chemotherapy. Recognition of this transient form of congenital leukemia is important to prevent the unnecessary use of toxic chemotherapeutic agents in such patients.

We performed exchange transfusions, utilizing the technique of automated erythrocytapheresis, for the treatment of patients with sickle cell anemia. In an attempt to determine guidelines for the use of erythrocytapheresis, we studied the use of this procedure in three distinct clinical situations in nine patients with sickle cell disease. Patients with dangerous complications of sickle cell disease such as acute respiratory distress and priapism responded well to erythrocytapheresis, showing marked improvement within 24-48 hours. Patients with prolonged painful vasoocclusive crises showed only variable improvement after erythrocytapheresis therapy, insufficient to justify exposing the patient to the risks of the procedure. Patients treated to decrease the frequency of painful crises demonstrated no prolongation in symptom-free intervals between crises. Therefore, erythrocytapheresis has its main value in the management of acute, dangerous complications of sickle cell disease.

A nine-year-old boy had typical clinical, hematologic and blood group serologic findings of autoimmune hemolytic anemia except for one important exception; with most commercially available broad spectrum anti-human sera the direct antiglobulin tests were negative. With reagents prepared in the laboratory which were found to be relatively less potent in and anti-IgG and IgM activity but which utilize a short period of incubation after mixing with the washed cells, the tests were all clearly positive. If incubation were employed with the commercial reagents, the tests were positive. Further studies showed that the patient's cells were coated exclusively with IgA and that a commercial reagent, although potent in anti-IgG and anti-IgM, was relatively deficient in anti-IgA. It is proposed that incubation compensates for the latter and is cautioned that incubation, with reagents potent in anti-IgG, could lead to false negative reactions with weakly IgG sensitized cells due to antibody surplus prozones of inhibition. This case illustrates that the rare instances of "Coombs negative immune hemolytic anemias" may be based on mechanisms such as those reported here and, that to be ideal, a broad spectrum anti-human serum should have balanced anti-immunoglobulin activities in relation to its incubation time.

The authors examined the pharmacokinetics of the CD19 receptor-directed tyrosine kinase inhibitor B43-Genistein in 17 patients (4 children, 13 adults) with B-lineage lymphoid malignancies, including 12 patients with acute lymphoblastic leukemia (ALL) and 5 patients with non-Hodgkin's lymphoma (NHL). The immunoconjugate was administered intravenously as a 1-hour continuous infusion at a dose level of either 0.1 mg/kg (N = 12) or 0.18 mg/kg (N = 5), and the plasma concentration-time data were modeled by using the WinNonlin program to estimate the pharmacokinetic parameters. Pharmacokinetic analyses revealed a plasma half-life of 19 +/- 4 hours, mean residence time of 22 +/- 4 hours, and a systemic clearance of 18 +/- 2 mL/h/kg. The average (mean +/- SEM) values for the maximum plasma concentration Cmax, volume of distribution at steady state (Vss), and area under curve (AUC) were 1092 +/- 225 ng/ml, 291 +/- 37 mL/kg, and 9987 +/- 2021 micrograms x h/L, respectively. The AUC values were higher at the 0.18 mg/kg dose level than at the 0.1 mg/kg dose level (16,848 +/- 5118 micrograms x h/L vs. 7128 +/- 1156 micrograms x h/L, p = 0.009). Patients with ALL had a significantly larger volume of distribution at steady state (332 +/- 47 mL/kg vs. 191 +/- 12 mL/kg, p = 0.04), faster clearance (21 +/- 3 mL/h/kg vs. 11 +/- 2 mL/h/kg, p = 0.03), and lower dose-corrected AUC than patients with NHL (6010 +/- 836 micrograms x h/L vs. 12,044 +/- 2707 micrograms x h/L, p = 0.006). There was a trend toward faster clearance rates (23 +/- 4 mL/h/kg vs. 16 +/- 3 mL/h/kg, p = 0.1), shorter elimination half-lives (5.7 +/- 3.6 hours vs. 13 +/- 8.8 hours, p = 0.1), and shorter mean residence times (11 +/- 3 hours vs. 25 +/- 5 hours, p = 0.08) for non-Caucasian patients as compared to Caucasian patients. When compared to adult patients, pediatric patients showed a significantly larger volume of distribution at steady state (418 +/- 82 mL/kg vs. 252 +/- 34 mL/kg, p = 0.02) and a longer elimination half-lives (18.4 +/- 13.6 hours vs. 8.7 +/- 6.7 hours, p = 0.04). The pharmacokinetics of B43-Genistein was not affected by the gender of the patients or by bone marrow transplantation in past medical history. Overall, B43-Genistein showed favorable pharmacokinetics in this heavily pretreated leukemia/lymphoma patient population, which is reminiscent of its recently reported favorable pharmacokinetics in cynomolgus monkeys. To our knowledge, this is the first clinical pharmacokinetics study of a tyrosine kinase inhibitor containing immunoconjugate.