[Relationship between Coombs-positive autoimmune hemolytic anemia and development of malignant tumors: a retrospective study].

Autoimmune hemolytic anemia (AIHA) is secondary to underlying diseases, such as autoimmune diseases and lymphoid malignancies. Recently, solid cancers have also been reported to be associated with AIHA, although there is not much information available. In this study, we retrospectively examined the correlation between AIHA and onset of malignancy in 100 patients diagnosed with AIHA based on the broad definition of AIHA at our hospital and cooperating institutions from January 1, 1995 to May 31, 2016. Malignancies were detected in 52 of the 100 patients (hematological malignancies: 39 patients; solid cancers: 22 patients; total malignancies including multiple primary malignancies: 67 patients). Of the 67 patients with malignancies, 28 were diagnosed with malignancies within 6 months of AIHA diagnosis. All patients with cold agglutinin disease (CAD) were associated with malignancies. Compared with warm AIHA, solid cancers were significantly more common among the patients with CAD. These findings emphasize the importance of investigating the malignancies upon diagnosis of AIHA.