Which of the following presents as mediastinal enlargement:

Answer is C (ALL) A young adolescent male presenting with a mediastinal mass is most often a precursor T cell The presence of a mediastinal mass is a characteristic feature of 'T' cell ALL. `Precursor T cell ALL is most often found in young men presenting with a large mediastinal mass' - Harrison Characteristic Features of T cell ALL (20% of ALL) Occurence in older children (adolescents) and adults Predilection for males Presence of anterior mediastinal mass in upto half of the cases at presentation (thymic mass) Early central nervous system involvement -(Early dissemination to meninges and testes) High WBC count often greater than 100,000/mm3