These algorithms address hematologic and oncologic problems affecting neonates, children and adolscents. Examining clinical problems which challenge the pediatrician, general practitioner and family practice physician, each algorithm utilizes a step-by-step approach based upon clues from the history, physical examination and laboratory studies. The algorithms addressing differential diagnosis clearly distinguish between the most common etiologies, those that are less frequent and finally some that are rare but important to recognize. CONTENTS Red cell disorders: initial evaluation of anaemia; microcytic anaemia; normocytic anaemia; macrocytic anaemia; pancytopenia; anaemia in the neonate; neonatal anaemia due to impaired RBC production; hemolytic aenemia; hemoglobinuria; presumed iron deficiency anaemia which fails to respond to oral iron; thalassemia; newborn screening for hemoglobinopathies; sickle cell anaemia with fever; management of painful vaso-occlusive episodes in sickle cell disease; evaluation and management of anemia in sickle cell disease; polycythemia (erythrocytosis); red cell transfusion. White cell disorders: leukocytosis; eosinophilia; neutropenia; the child with recurrent infection - leukocyte dysfunction. Reticuloendothelial disorders: llymphadenopathy - generalized lymphadenopathy; lymphadenopathy - localized adenopathy; splenomegaly. Coagulation disorders: evaluation of a child with bleeding or abnormal coagulation screening tests; evaluation of a child with thrombocytopenia; thrombocytopenia in the well neonate; thrombocytopenia in the ill neonate; platelet dysfunction; thrombocytosis; treatment of bleeding in children with hemophilia; evaluation of a child with hemophilia who fails infusion therapy; consumptive coagulopathy; thrombophilia evaluation in a newborn infant with thrombosis; thrombophilia evaluation in a child with thrombosis. Malignant disorders: assessment of a child with suspected leukaemia; assessment of a mediastinal mass; assessment of an abdominal mass; assessment of a pelvic mass; assessment of a soft tissue mass; assessment of bone lesions; initial management of a child with a newly diagnosed brain tumor; supratentorial brain tumors; brain tumors of the posterior fossa, brain stem and visual pathway; initial management of a child with a tumor involving or near the spinal cord; recognition and management of tumor lysis syndrome; recognition and management of superior vena cava syndrome; febrile neutropenia; management of biopsy tissue in children with possible malignancies; diagnosis and management of pulmonary infiltrates during chemotherapy; monitoring for late effects in children with malignancies; useful normal laboratory values. ory values.