Table 1. Timeline of the Case.

Time point	Event	Description
Day 0	Patient presented with SOB	CXR showed right pleural effusion
Day 5	Pleurocentesis	Exudative fluid
Day 8	Echocardiogram	Pericardial effusion
Day 15	Chest CT scan	Posterior mediastinal mass
Day 18	Mediastinal mass biopsy	Myeloid sarcoma
Day 19	PET scan	Bulky hypermetabolic mediastinal mass with bone marrow hyperactivity
Day 28	Bone marrow aspirate	AUL

SOB: shortness of breath; CXR: chest X-ray; CT: computed tomography; PET: positron emission tomography; AUL: acute undifferentiated leukemia.