An elderly gentleman is sent to the emergency department by his primary care physician. He complains of dark intraoral lesions that appear and disappear for the last 2-3 days. He also complained of generalized weakness and dark, foul-smelling stools.

What is on your differential diagnosis? Diagnostic workup? .

(Scroll down for Case Conclusion)

Diagnosis: Idiopathic Thrombocytopenic Purpura (ITP)

Case Conclusion: The patient was diagnosed with ITP, likely related to an underlying (and previously unknown) pulmonary malignancy. Further skin exam revealed diffuse petechiae covering the lower extremities. His platelet count was 5 x 10^9/L and he was found to have acute blood loss anemia due to an ongoing upper GI bleed: