Evans' syndrome as a presenting manifestation of atypical paroxysmal cold hemoglobinuria.

Paroxysmal cold hemoglobinuria is a rare and potentially life-threatening acquired hemolytic anemia occurring either as an acute transient anemia following several different viral syndromes, or in a chronic idiopathic form. Episodic hemolysis in paroxysmal cold hemoglobinuria is usually associated with a biphasic (Donath-Landsteiner) IgG cold-reactive complement-fixing autohemolysin with anti-P specificity. Paroxysmal cold hemoglobinuria has not previously been associated with malignancy nor has it been clearly shown to be steroid-responsive. This report describes a patient with steroid-responsive autoimmune hemolytic anemia and immune thrombocytopenia (Evans' syndrome) associated with oat cell carcinoma of the lung and a unique biphasic anti-IgM autohemolysin. This case extends the spectrum of biphasic antibody-mediated immune cytopenias and widens both the clinical and the serologic definition of paroxysmal cold hemoglobinuria.