<prompt> A family of a child just diagnosed wit acute lymphoblastic leukemia asks about the childs prognosis. Which of the following is a poor prognostic indicator ?Presence of mediastinal massAge between 1 and 10 yearsHyperploidy with more than 50 chromosomesWBC count less than 50,000mm3 at diagnosis  <response>: Presence of a large mediastinal mass can lead to tracheal compression,producing tachypnoea respiratory distresssuperior mediastinal syndrome.A large mediastinal mass may sometimes cause superior vena cava syndrome with facial edema and plethora,throbbing headache,conjunctival congestion,and dilated neck veins.So mediastinal mass is a poor prognostic factor. The presence of hyperploidychromosome number 50,DNA index1.16 is associated with good prognosis.Other good prognostic factors are : total WBC count 50,000mm3 and age between 1-10 years. Reference:Essential pediatrics-Ghai,8th edition,page no:600,601. 