CONCLUSION:
Although pericardial effusion is rare as the first demonstration of
pediatric mediastinal lymphoma, it is important to take this
differential diagnosis into consideration. Because non-Hodgkin lymphomas
with mediastinal disease at presentation have a natural tendency for
rapid dissemination and worse prognosis when invading the pericardium,
hence minimal delay in diagnosis is essential to avoid incorrect initial
management and initiate the true approach as soon as possible.