An unusual cause of spontaneous bleeding in the intensive care unit - mastocytosis: a case report.

We report the case of a 39-year old male patient who presented with anaphylactoid shock and diffuse bleeding with prolonged activated partial thromboplastin time at the emergency room. The diagnosis of aggressive mastocytosis was suspected and then confirmed by raised tryptase level and mastocytic infiltration of the bone marrow. The outcome was favorable with supportive measures, antihistamine drugs, and imatinib mesylate.